Climatic and climatic factors play a very important role in the growth and
development of plants.... more Climatic and climatic factors play a very important role in the growth and development of plants. And are considered as controllable, effective and agricultural variables. Plant tolerance thresholds are limited in relation to each of the meteorological parameters and have the ability to grow and develop biological activity in a certain heat range, and any anomaly on these parameters can have direct and indirect effects on agricultural production. Stressors alter and disrupt the physiological processes of plants. And from this change, they affect the production of crops. Cold stress is one of the most important environmental factors that reduces the yield of crops in autumn crops in subtropical regions. The damage caused by frost to crops varies depending on the species and cultivar. And this action is often caused by autumn frosts. For any part of Qom, not only there is a favorable temperature, but also the growth stages and various activities of plants, with ideal temperatures as well as lethal temperature range and minimum and maximum, reducing the temperature of The minimum plant tolerance threshold can be harmful.
In this article, we first find out in a specialized way how the size of particles increases and d... more In this article, we first find out in a specialized way how the size of particles increases and decreases, then we define each of these two categories and explain the equilibrium equations of the population of particles in different sections and show the changes in the size of particles with the passage of time. , about the electric double layer, we discuss various processes of particles such as creation, accumulation, death, disintegration, aggregation, nucleation, breakdown, how the particles shrink and grow, and the equilibrium equations of particles in gas, liquid and solid environments. we show Particle population balances are discussed in Sect. Checking the balance of the population of particles is an optimal task in the industry and the production of chemical fertilizers, etc.
Iranian International Journal of Science, Culture and Art, 2021
Computational fluid dynamics (CFD) is one of the methods in which the efficiency
of fluids is exa... more Computational fluid dynamics (CFD) is one of the methods in which the efficiency of fluids is examined in various ways; For these fluids, equations are considered that are specific to the fluid and its single-phase, biphasic and multi-phase. One of the equations used in these methods is the drag force which has a drag coefficient; The drag coefficient used here is for liquefied gas systems, systems in which the gas bubble and the liquid, which is usually water, come into contact at the separation surface and a slip occurs at this level, which is the drag force. To follow. Among the coordinates used for calculations, Euler-Euler, Euler-Lagrange and etc. The coordinates we are considering are Euler-Eulerian. The equations used in various CFD probes are for Newtonian fluids, usually for sieve trays and etc Used. In this study, we review the drag coefficients that have been obtained by researchers in this framework over the years.
Iranian International Journal of Science, Culture and Art, 2021
The traveling salesman is one of the NP-Complete problems that many researchers
have worked on so... more The traveling salesman is one of the NP-Complete problems that many researchers have worked on so that they can either solve this problem in general or take it a few steps further. In this article, we also present a new solution. In order to be able to solve this problem close to a complete solution, and in our new solution, it identifies and solves the three main problems facing the traveling salesman route, namely deadlock, intersection and critical routes, and finally the route for The vendor offers a path that is free of the above three problems, and the simulation results of the new solution also show that our solution has been able to be superior to previous solutions, all of which are the advantages of our new solution.
در این مقاله ما ابتدا به صورت تخصصی چگونگی بزرگ شدن و کوچک شدن اندازه ذرات را پی می گیری م
سپس هر... more در این مقاله ما ابتدا به صورت تخصصی چگونگی بزرگ شدن و کوچک شدن اندازه ذرات را پی می گیری م سپس هر کدام از این دو مقوله را تع ریف کرده معادلات موازنه جمعیت ذرات را در بخش های مختلف شرح داده تغییرات اندازه ذرات را با گذشت زمان نشان میدهیم، در مورد لایه مضاعف الکتریکی بحث می کنیم فرآیندهای مختلف ذرات مانند پیدایش، تجمع مرگ، متلاشی شدن، توده دارشدن، هسته دار شدن، شکست، چگونگی کوچک و بزرگ شدن ذرات و معادلات موازنه ذرات در محیط های گاز، مایع و جامد را بررسی می نماییم. تعادل جمعیت ذرات در بخش بررسی می شوند. بررسی موازنه جمعیت ذرات کاری بهینه در صنعت و تولید کودهای شیمیایی و غیره است.
ز جمله روش هایی است که در آن کارایی سیالات از راه هاي گوناگون (CFD) دینامیک سیالات محاسباتی
مورد ... more ز جمله روش هایی است که در آن کارایی سیالات از راه هاي گوناگون (CFD) دینامیک سیالات محاسباتی مورد بررسی قرار می گیرد ; براي این سیالات معادلاتی در نظر گرفته می شود که ویژه آن سیال و یک فازي ، دو فازي و چند فازي بودن آن است . از جمله معادلاتی که در این روش ها بکار می رود نیروي پسا است که ضریب پسا را به همراه دارد ; ضریب پسایی که در اینجا بکار برده می شود ،براي سیستم هاي گاز مایع است ، سیستم هایی که در آن حباب گاز و مایع که معمولا آب است ،در سطح جدایشی با هم تماس دارند و لغزشی در این سطح به بار می آید که نیروي پسا را به دنبال دارد . از جمله مختصاتی که براي محاسبات به کار گرفته می شود ، اویلر – اویلري ، اویلر - لاگرانژي و . . . است که مختصات مورد بررسی ما اویلر – اویلري است . معادلاتی که در کاوش به کار برده شده است براي سیالات نیوتنی است که معمولا براي سینی هاي غربالی و . . . CFD هاي گوناگون بکار برده شده است . در این پژوهش مروري می کنیم بر ضرائب پسایی که در این چارچوب و در طی سالیان دور توسط پژوهشگران بدست آمده اند .
است که تا کنون محققین بسیاري NP- Complate فروشنده دوره گرد از مسائل
روي آن کار کرده اند تا بتوانن... more است که تا کنون محققین بسیاري NP- Complate فروشنده دوره گرد از مسائل روي آن کار کرده اند تا بتوانند یا این مشکل را بصورت کلی حل یا حل آن را چند قدم جلوتر ببرند که ما نیز در این مقاله یک راه کار جدید را ارائه کرده ایم تا بتوانیم حل این مسائله را به حل کامل نزدیک کرده و در راهکار جدید ما سه مشکل اصلی پیش روي مسیر فروشنده دوره گرد یعنی بن بست، تقاطع و مسیر هاي بحرانی را تشخیص و اقدام به رفع آنها کنید و در نهایت مسیري را که براي فروشنده ارائه می دهد یک مسیري که خالی از سه مشکل بالاست، می باشد و نتایج شبیه سازي راهکار جدید نیز نشان دهنده این است که راهکار ما توانسته است نسبت به راهکارهاي گذشته برتري داشته باشد که همه این ها از مزایاي راهکار نو ما است.
عوامل آب و هوایی و اقلیمی نقش بسیاري در رشد و توسعه گیاهان دارد وجز متغیر هاي قابل کنترل و اثر گذ... more عوامل آب و هوایی و اقلیمی نقش بسیاري در رشد و توسعه گیاهان دارد وجز متغیر هاي قابل کنترل و اثر گذار در بخش کشاورزي محسوب می شود. آستانه تحمل گیاهان در رابطه با پارامتر هاي هواشناسی محدود است و در دامنه گرمایی مشخصی قابلیت رشد و فعایت زیستی دارد.. هر ناهنجاري بر این پارامتر ها به صورت مستقیم و غیر مستقیم بر تولیدات کشاورزي اثرات زیادي دارد. عوامل تنش زا باعث تغییر و اختلال در فرآیند هاي فیزیولوژیکی می شودو به این گونه تولید گیاهان زراعی را تحت تاثیر قرار می دهد. تنش سرما از عوامل محیطی است سبب کاهش عملکرد محصولات در کشت پاییزه در مناطق نیمه گرمسیري می شود. آسیب هاي ناشی از سرمازدگی به محصولات زراعی بسته به رقم و گونه مختلف است. این عمل ناشی از سرمازدگی زودرس پاییزه است. براي هر رقم نه تنها درجه حرارت مطلوب است بلکه فعالیت رشد و فعالیت هاي گوناگون گیاهان داراي فعالیت هاي ایده آل محدوده حرارتی کشنده و کمینه و بیشینه است. کاهش دما از آستانه تحمل کمینه گیاه خسارت زا باشد.
In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed l... more In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed laminar flow for 7 cases. Variation of entropy generation and enthalpy are shown along the radius. Entropy generation and enthalpy along the radius are obtained. Heat transfer is increased with the flow of fluid through the pipe, in inlet of pipe points to the output. The amount of entropy generation in the pipes of higher temperature is more than other points. Enthalpy is proportional to temperature in surface variation of 7 cases. In the points of higher temperature in elementary cases, the enthalpy value is increasing and it is increasing in other cases. Fluctuations of enthalpy and entropy generation are producted in interface points of pipe surfaces. The diagram data can be used to measure the minimum entropy generation in pipe heat transfer. Minimum entropy generation is in surface whit high temperature. The enthalpy in centerline is constant and inlet enthalpy of the tube is greater than other point with higher temperatures in radial flow. The lowest enthalpy is obtained in tubes with lowest initial temperature (case 7). Minimum entropy generation is presented in surface whit high temperature at the beginning (case 1-3) or high at the ending (case 5-7).
Heat flux is passed through the tube wall with natural convection in a tube wall of developed lam... more Heat flux is passed through the tube wall with natural convection in a tube wall of developed laminar flow. Tubes are used to find the best case with the minimum enthalpy and entropy generation. Process of heat flux pass is simulated with natural convection in several cases through the wall. By varying heat flux along the tube kept in touch with natural convection, temperature, entropy generation and enthalpy of each case change. Tubes are studied distribution of temperature, entropy generation and enthalpy along the radius and distribution of entropy generation and enthalpy along the cylinder axis, via different diagrams. Entering heat flux to the tube wall, temperature, entropy generation and enthalpy of the fluid increase significantly along the radius. The contact of heat flux to the tube wall in the direction of fluid movement, entropy generation decreases in the flow direction. Heat flux is applied to the tube wall, in parts of the tube being a heat flux, enthalpy increases in the direction of the tube wall. enthalpy is reduced in the tube wall in parts that are associated with the natural convection. The electric coil is wrapped on the tube as heat flux in tubes that are in contact with convection, the implications of this paper is used.
Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the be... more Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the best case with at least enthalpy and minimum entropy generation, through pipe wall having radiant flow. Flow in developed laminar conditions is investigated. Radiant flow is simulated Passing the natural convection on the wall with for 6 cases. Variation of radiation along the pipe touching with natural convection causes to change temperature, entropy generation and enthalpy for each case. Different profiles are investigated distributions of temperature, entropy generation and enthalpy along the radius. Along the wall are shown variation in enthalpy and entropy generation. There have been increased in radiationconvection boundary conditions temperature, enthalpy as well as entropy generation. Along the radius and axis have appropriately been increased in radiation boundary conditions than convection, the amounts of enthalpy. Near the wall are occurred the most changes in temperature, enthalpy and entropy generation. Application the thermal boundary conditions are used for minimum entropy generation make fluid with high prandtl number to become high thermal carrier. Solar radiation application are used in Parabolic Trough, Parabolic Dish, Solar Chimney and tube furnace in various cases. Application are used for minimum entropy generation.
Heat flux is passed through the tube wall with natural convection in a tube wall of developed lam... more Heat flux is passed through the tube wall with natural convection in a tube wall of developed laminar flow. Tubes are used to find the best case with the minimum enthalpy and entropy generation. Process of heat flux pass is simulated with natural convection in several cases through the wall. By varying heat flux along the tube kept in touch with natural convection, temperature, entropy generation and enthalpy of each case change. Tubes are studied distribution of temperature, entropy generation and enthalpy along the radius and distribution of entropy generation and enthalpy along the cylinder axis, via different diagrams. Entering heat flux to the tube wall, temperature, entropy generation and enthalpy of the fluid increase significantly along the radius. The contact of heat flux to the tube wall in the direction of fluid movement, entropy generation decreases in the flow direction. Heat flux is applied to the tube wall, in parts of the tube being a heat flux, enthalpy increases in...
In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed l... more In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed laminar flow for 7 cases. Variation of entropy generation and enthalpy are shown along the radius. Entropy generation and enthalpy along the radius are obtained. Heat transfer is increased with the flow of fluid through the pipe, in inlet of pipe points to the output. The amount of entropy generation in the pipes of higher temperature is more than other points. Enthalpy is proportional to temperature in surface variation of 7 cases. In the points of higher temperature in elementary cases, the enthalpy value is increasing and it is increasing in other cases. Fluctuations of enthalpy and entropy generation are producted in interface points of pipe surfaces. The diagram data can be used to measure the minimum entropy generation in pipe heat transfer. Minimum entropy generation is in surface whit high temperature. The enthalpy in centerline is constant and inlet enthalpy of the tube is greate...
Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the be... more Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the best case with at least enthalpy and minimum entropy generation, through pipe wall having radiant flow. Flow in developed laminar conditions is investigated. Radiant flow is simulated Passing the natural convection on the wall with for 6 cases. Variation of radiation along the pipe touching with natural convection causes to change temperature, entropy generation and enthalpy for each case. Different profiles are investigated distributions of temperature, entropy generation and enthalpy along the radius. Along the wall are shown variation in enthalpy and entropy generation. There have been increased in radiation-convection boundary conditions temperature, enthalpy as well as entropy generation. Along the radius and axis have appropriately been increased in radiation boundary conditions than convection, the amounts of enthalpy. Near the wall are occurred the most changes in temperature, enth...
In a boundary wall of a pipe for developed laminar flow, to find the best example in which the le... more In a boundary wall of a pipe for developed laminar flow, to find the best example in which the least enthalpy and entropy are created, non-uniform distribution of convective flow in wall is studied. Some factors are simulated for transfer coefficient heat variations of moving the pipe. Distribution of temperature, entropy and enthalpy along the radius and distribution of generated entropy and enthalpy along the tube axis are shown. Entropy and enthalpy are reduced along the axis. Entropy, except some areas close to the wall, is increasing along the radius. Temperature and enthalpy, approaching the wall along the radius, have increased.
Drag coefficient independent on bubble diameter is required to ease design sieve trays or bubble ... more Drag coefficient independent on bubble diameter is required to ease design sieve trays or bubble column, through simulation of computational fluid dynamic. In this paper, the drag coefficients, independent or dependent on the diameter, are reviewed for gas-liquid system. A number of drag coefficients are used for Computational Fluid Dynamics (CFD). Different forces are entered to the liquid-bubble separation surface in diverse directions. Forces are investigated with mathematical proving for Newtonian fluids and Eulerian coordinate. Finally, the external force as a new force, enter to the drag coefficient equations. Drag coefficient is included force coefficient. Drag force is entered in momentum equations. Drag coefficient is used in two-phase systems which bubbles and liquid are activated as dispersed and continuous phase, respectively. Bubbles and liquid are in contact with each other in separation surface on bubble. Drag force is created slip on separation surface. The drag coef...
Climatic and climatic factors play a very important role in the growth and
development of plants.... more Climatic and climatic factors play a very important role in the growth and development of plants. And are considered as controllable, effective and agricultural variables. Plant tolerance thresholds are limited in relation to each of the meteorological parameters and have the ability to grow and develop biological activity in a certain heat range, and any anomaly on these parameters can have direct and indirect effects on agricultural production. Stressors alter and disrupt the physiological processes of plants. And from this change, they affect the production of crops. Cold stress is one of the most important environmental factors that reduces the yield of crops in autumn crops in subtropical regions. The damage caused by frost to crops varies depending on the species and cultivar. And this action is often caused by autumn frosts. For any part of Qom, not only there is a favorable temperature, but also the growth stages and various activities of plants, with ideal temperatures as well as lethal temperature range and minimum and maximum, reducing the temperature of The minimum plant tolerance threshold can be harmful.
In this article, we first find out in a specialized way how the size of particles increases and d... more In this article, we first find out in a specialized way how the size of particles increases and decreases, then we define each of these two categories and explain the equilibrium equations of the population of particles in different sections and show the changes in the size of particles with the passage of time. , about the electric double layer, we discuss various processes of particles such as creation, accumulation, death, disintegration, aggregation, nucleation, breakdown, how the particles shrink and grow, and the equilibrium equations of particles in gas, liquid and solid environments. we show Particle population balances are discussed in Sect. Checking the balance of the population of particles is an optimal task in the industry and the production of chemical fertilizers, etc.
Iranian International Journal of Science, Culture and Art, 2021
Computational fluid dynamics (CFD) is one of the methods in which the efficiency
of fluids is exa... more Computational fluid dynamics (CFD) is one of the methods in which the efficiency of fluids is examined in various ways; For these fluids, equations are considered that are specific to the fluid and its single-phase, biphasic and multi-phase. One of the equations used in these methods is the drag force which has a drag coefficient; The drag coefficient used here is for liquefied gas systems, systems in which the gas bubble and the liquid, which is usually water, come into contact at the separation surface and a slip occurs at this level, which is the drag force. To follow. Among the coordinates used for calculations, Euler-Euler, Euler-Lagrange and etc. The coordinates we are considering are Euler-Eulerian. The equations used in various CFD probes are for Newtonian fluids, usually for sieve trays and etc Used. In this study, we review the drag coefficients that have been obtained by researchers in this framework over the years.
Iranian International Journal of Science, Culture and Art, 2021
The traveling salesman is one of the NP-Complete problems that many researchers
have worked on so... more The traveling salesman is one of the NP-Complete problems that many researchers have worked on so that they can either solve this problem in general or take it a few steps further. In this article, we also present a new solution. In order to be able to solve this problem close to a complete solution, and in our new solution, it identifies and solves the three main problems facing the traveling salesman route, namely deadlock, intersection and critical routes, and finally the route for The vendor offers a path that is free of the above three problems, and the simulation results of the new solution also show that our solution has been able to be superior to previous solutions, all of which are the advantages of our new solution.
در این مقاله ما ابتدا به صورت تخصصی چگونگی بزرگ شدن و کوچک شدن اندازه ذرات را پی می گیری م
سپس هر... more در این مقاله ما ابتدا به صورت تخصصی چگونگی بزرگ شدن و کوچک شدن اندازه ذرات را پی می گیری م سپس هر کدام از این دو مقوله را تع ریف کرده معادلات موازنه جمعیت ذرات را در بخش های مختلف شرح داده تغییرات اندازه ذرات را با گذشت زمان نشان میدهیم، در مورد لایه مضاعف الکتریکی بحث می کنیم فرآیندهای مختلف ذرات مانند پیدایش، تجمع مرگ، متلاشی شدن، توده دارشدن، هسته دار شدن، شکست، چگونگی کوچک و بزرگ شدن ذرات و معادلات موازنه ذرات در محیط های گاز، مایع و جامد را بررسی می نماییم. تعادل جمعیت ذرات در بخش بررسی می شوند. بررسی موازنه جمعیت ذرات کاری بهینه در صنعت و تولید کودهای شیمیایی و غیره است.
ز جمله روش هایی است که در آن کارایی سیالات از راه هاي گوناگون (CFD) دینامیک سیالات محاسباتی
مورد ... more ز جمله روش هایی است که در آن کارایی سیالات از راه هاي گوناگون (CFD) دینامیک سیالات محاسباتی مورد بررسی قرار می گیرد ; براي این سیالات معادلاتی در نظر گرفته می شود که ویژه آن سیال و یک فازي ، دو فازي و چند فازي بودن آن است . از جمله معادلاتی که در این روش ها بکار می رود نیروي پسا است که ضریب پسا را به همراه دارد ; ضریب پسایی که در اینجا بکار برده می شود ،براي سیستم هاي گاز مایع است ، سیستم هایی که در آن حباب گاز و مایع که معمولا آب است ،در سطح جدایشی با هم تماس دارند و لغزشی در این سطح به بار می آید که نیروي پسا را به دنبال دارد . از جمله مختصاتی که براي محاسبات به کار گرفته می شود ، اویلر – اویلري ، اویلر - لاگرانژي و . . . است که مختصات مورد بررسی ما اویلر – اویلري است . معادلاتی که در کاوش به کار برده شده است براي سیالات نیوتنی است که معمولا براي سینی هاي غربالی و . . . CFD هاي گوناگون بکار برده شده است . در این پژوهش مروري می کنیم بر ضرائب پسایی که در این چارچوب و در طی سالیان دور توسط پژوهشگران بدست آمده اند .
است که تا کنون محققین بسیاري NP- Complate فروشنده دوره گرد از مسائل
روي آن کار کرده اند تا بتوانن... more است که تا کنون محققین بسیاري NP- Complate فروشنده دوره گرد از مسائل روي آن کار کرده اند تا بتوانند یا این مشکل را بصورت کلی حل یا حل آن را چند قدم جلوتر ببرند که ما نیز در این مقاله یک راه کار جدید را ارائه کرده ایم تا بتوانیم حل این مسائله را به حل کامل نزدیک کرده و در راهکار جدید ما سه مشکل اصلی پیش روي مسیر فروشنده دوره گرد یعنی بن بست، تقاطع و مسیر هاي بحرانی را تشخیص و اقدام به رفع آنها کنید و در نهایت مسیري را که براي فروشنده ارائه می دهد یک مسیري که خالی از سه مشکل بالاست، می باشد و نتایج شبیه سازي راهکار جدید نیز نشان دهنده این است که راهکار ما توانسته است نسبت به راهکارهاي گذشته برتري داشته باشد که همه این ها از مزایاي راهکار نو ما است.
عوامل آب و هوایی و اقلیمی نقش بسیاري در رشد و توسعه گیاهان دارد وجز متغیر هاي قابل کنترل و اثر گذ... more عوامل آب و هوایی و اقلیمی نقش بسیاري در رشد و توسعه گیاهان دارد وجز متغیر هاي قابل کنترل و اثر گذار در بخش کشاورزي محسوب می شود. آستانه تحمل گیاهان در رابطه با پارامتر هاي هواشناسی محدود است و در دامنه گرمایی مشخصی قابلیت رشد و فعایت زیستی دارد.. هر ناهنجاري بر این پارامتر ها به صورت مستقیم و غیر مستقیم بر تولیدات کشاورزي اثرات زیادي دارد. عوامل تنش زا باعث تغییر و اختلال در فرآیند هاي فیزیولوژیکی می شودو به این گونه تولید گیاهان زراعی را تحت تاثیر قرار می دهد. تنش سرما از عوامل محیطی است سبب کاهش عملکرد محصولات در کشت پاییزه در مناطق نیمه گرمسیري می شود. آسیب هاي ناشی از سرمازدگی به محصولات زراعی بسته به رقم و گونه مختلف است. این عمل ناشی از سرمازدگی زودرس پاییزه است. براي هر رقم نه تنها درجه حرارت مطلوب است بلکه فعالیت رشد و فعالیت هاي گوناگون گیاهان داراي فعالیت هاي ایده آل محدوده حرارتی کشنده و کمینه و بیشینه است. کاهش دما از آستانه تحمل کمینه گیاه خسارت زا باشد.
In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed l... more In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed laminar flow for 7 cases. Variation of entropy generation and enthalpy are shown along the radius. Entropy generation and enthalpy along the radius are obtained. Heat transfer is increased with the flow of fluid through the pipe, in inlet of pipe points to the output. The amount of entropy generation in the pipes of higher temperature is more than other points. Enthalpy is proportional to temperature in surface variation of 7 cases. In the points of higher temperature in elementary cases, the enthalpy value is increasing and it is increasing in other cases. Fluctuations of enthalpy and entropy generation are producted in interface points of pipe surfaces. The diagram data can be used to measure the minimum entropy generation in pipe heat transfer. Minimum entropy generation is in surface whit high temperature. The enthalpy in centerline is constant and inlet enthalpy of the tube is greater than other point with higher temperatures in radial flow. The lowest enthalpy is obtained in tubes with lowest initial temperature (case 7). Minimum entropy generation is presented in surface whit high temperature at the beginning (case 1-3) or high at the ending (case 5-7).
Heat flux is passed through the tube wall with natural convection in a tube wall of developed lam... more Heat flux is passed through the tube wall with natural convection in a tube wall of developed laminar flow. Tubes are used to find the best case with the minimum enthalpy and entropy generation. Process of heat flux pass is simulated with natural convection in several cases through the wall. By varying heat flux along the tube kept in touch with natural convection, temperature, entropy generation and enthalpy of each case change. Tubes are studied distribution of temperature, entropy generation and enthalpy along the radius and distribution of entropy generation and enthalpy along the cylinder axis, via different diagrams. Entering heat flux to the tube wall, temperature, entropy generation and enthalpy of the fluid increase significantly along the radius. The contact of heat flux to the tube wall in the direction of fluid movement, entropy generation decreases in the flow direction. Heat flux is applied to the tube wall, in parts of the tube being a heat flux, enthalpy increases in the direction of the tube wall. enthalpy is reduced in the tube wall in parts that are associated with the natural convection. The electric coil is wrapped on the tube as heat flux in tubes that are in contact with convection, the implications of this paper is used.
Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the be... more Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the best case with at least enthalpy and minimum entropy generation, through pipe wall having radiant flow. Flow in developed laminar conditions is investigated. Radiant flow is simulated Passing the natural convection on the wall with for 6 cases. Variation of radiation along the pipe touching with natural convection causes to change temperature, entropy generation and enthalpy for each case. Different profiles are investigated distributions of temperature, entropy generation and enthalpy along the radius. Along the wall are shown variation in enthalpy and entropy generation. There have been increased in radiationconvection boundary conditions temperature, enthalpy as well as entropy generation. Along the radius and axis have appropriately been increased in radiation boundary conditions than convection, the amounts of enthalpy. Near the wall are occurred the most changes in temperature, enthalpy and entropy generation. Application the thermal boundary conditions are used for minimum entropy generation make fluid with high prandtl number to become high thermal carrier. Solar radiation application are used in Parabolic Trough, Parabolic Dish, Solar Chimney and tube furnace in various cases. Application are used for minimum entropy generation.
Heat flux is passed through the tube wall with natural convection in a tube wall of developed lam... more Heat flux is passed through the tube wall with natural convection in a tube wall of developed laminar flow. Tubes are used to find the best case with the minimum enthalpy and entropy generation. Process of heat flux pass is simulated with natural convection in several cases through the wall. By varying heat flux along the tube kept in touch with natural convection, temperature, entropy generation and enthalpy of each case change. Tubes are studied distribution of temperature, entropy generation and enthalpy along the radius and distribution of entropy generation and enthalpy along the cylinder axis, via different diagrams. Entering heat flux to the tube wall, temperature, entropy generation and enthalpy of the fluid increase significantly along the radius. The contact of heat flux to the tube wall in the direction of fluid movement, entropy generation decreases in the flow direction. Heat flux is applied to the tube wall, in parts of the tube being a heat flux, enthalpy increases in...
In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed l... more In this article, Entropy generation and enthalpy are investigated on the pipe wall in developed laminar flow for 7 cases. Variation of entropy generation and enthalpy are shown along the radius. Entropy generation and enthalpy along the radius are obtained. Heat transfer is increased with the flow of fluid through the pipe, in inlet of pipe points to the output. The amount of entropy generation in the pipes of higher temperature is more than other points. Enthalpy is proportional to temperature in surface variation of 7 cases. In the points of higher temperature in elementary cases, the enthalpy value is increasing and it is increasing in other cases. Fluctuations of enthalpy and entropy generation are producted in interface points of pipe surfaces. The diagram data can be used to measure the minimum entropy generation in pipe heat transfer. Minimum entropy generation is in surface whit high temperature. The enthalpy in centerline is constant and inlet enthalpy of the tube is greate...
Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the be... more Convection flow is passed in a pipe wall possessing radiation-convection, in order to find the best case with at least enthalpy and minimum entropy generation, through pipe wall having radiant flow. Flow in developed laminar conditions is investigated. Radiant flow is simulated Passing the natural convection on the wall with for 6 cases. Variation of radiation along the pipe touching with natural convection causes to change temperature, entropy generation and enthalpy for each case. Different profiles are investigated distributions of temperature, entropy generation and enthalpy along the radius. Along the wall are shown variation in enthalpy and entropy generation. There have been increased in radiation-convection boundary conditions temperature, enthalpy as well as entropy generation. Along the radius and axis have appropriately been increased in radiation boundary conditions than convection, the amounts of enthalpy. Near the wall are occurred the most changes in temperature, enth...
In a boundary wall of a pipe for developed laminar flow, to find the best example in which the le... more In a boundary wall of a pipe for developed laminar flow, to find the best example in which the least enthalpy and entropy are created, non-uniform distribution of convective flow in wall is studied. Some factors are simulated for transfer coefficient heat variations of moving the pipe. Distribution of temperature, entropy and enthalpy along the radius and distribution of generated entropy and enthalpy along the tube axis are shown. Entropy and enthalpy are reduced along the axis. Entropy, except some areas close to the wall, is increasing along the radius. Temperature and enthalpy, approaching the wall along the radius, have increased.
Drag coefficient independent on bubble diameter is required to ease design sieve trays or bubble ... more Drag coefficient independent on bubble diameter is required to ease design sieve trays or bubble column, through simulation of computational fluid dynamic. In this paper, the drag coefficients, independent or dependent on the diameter, are reviewed for gas-liquid system. A number of drag coefficients are used for Computational Fluid Dynamics (CFD). Different forces are entered to the liquid-bubble separation surface in diverse directions. Forces are investigated with mathematical proving for Newtonian fluids and Eulerian coordinate. Finally, the external force as a new force, enter to the drag coefficient equations. Drag coefficient is included force coefficient. Drag force is entered in momentum equations. Drag coefficient is used in two-phase systems which bubbles and liquid are activated as dispersed and continuous phase, respectively. Bubbles and liquid are in contact with each other in separation surface on bubble. Drag force is created slip on separation surface. The drag coef...
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Papers by reza kakulvand
development of plants. And are considered as controllable, effective and agricultural
variables. Plant tolerance thresholds are limited in relation to each of the
meteorological parameters and have the ability to grow and develop biological
activity in a certain heat range, and any anomaly on these parameters can have direct
and indirect effects on agricultural production. Stressors alter and disrupt the
physiological processes of plants. And from this change, they affect the production
of crops. Cold stress is one of the most important environmental factors that reduces
the yield of crops in autumn crops in subtropical regions. The damage caused by
frost to crops varies depending on the species and cultivar. And this action is often
caused by autumn frosts. For any part of Qom, not only there is a favorable
temperature, but also the growth stages and various activities of plants, with ideal
temperatures as well as lethal temperature range and minimum and maximum,
reducing the temperature of The minimum plant tolerance threshold can be harmful.
of fluids is examined in various ways; For these fluids, equations are considered that
are specific to the fluid and its single-phase, biphasic and multi-phase. One of the
equations used in these methods is the drag force which has a drag coefficient; The
drag coefficient used here is for liquefied gas systems, systems in which the gas
bubble and the liquid, which is usually water, come into contact at the separation
surface and a slip occurs at this level, which is the drag force. To follow. Among the
coordinates used for calculations, Euler-Euler, Euler-Lagrange and etc. The
coordinates we are considering are Euler-Eulerian. The equations used in various
CFD probes are for Newtonian fluids, usually for sieve trays and etc Used. In this
study, we review the drag coefficients that have been obtained by researchers in this
framework over the years.
have worked on so that they can either solve this problem in general or take it a
few steps further. In this article, we also present a new solution. In order to be able
to solve this problem close to a complete solution, and in our new solution, it
identifies and solves the three main problems facing the traveling salesman route,
namely deadlock, intersection and critical routes, and finally the route for The
vendor offers a path that is free of the above three problems, and the simulation
results of the new solution also show that our solution has been able to be superior
to previous solutions, all of which are the advantages of our new solution.
سپس هر کدام از این دو مقوله را تع ریف کرده معادلات موازنه جمعیت ذرات را در بخش های مختلف شرح داده
تغییرات اندازه ذرات را با گذشت زمان نشان میدهیم، در مورد لایه مضاعف الکتریکی بحث می کنیم فرآیندهای
مختلف ذرات مانند پیدایش، تجمع مرگ، متلاشی شدن، توده دارشدن، هسته دار شدن، شکست، چگونگی
کوچک و بزرگ شدن ذرات و معادلات موازنه ذرات در محیط های گاز، مایع و جامد را بررسی می نماییم. تعادل
جمعیت ذرات در بخش بررسی می شوند. بررسی موازنه جمعیت ذرات کاری بهینه در صنعت و تولید کودهای
شیمیایی و غیره است.
مورد بررسی قرار می گیرد ; براي این سیالات معادلاتی در نظر گرفته می شود که ویژه آن سیال و یک فازي ، دو
فازي و چند فازي بودن آن است . از جمله معادلاتی که در این روش ها بکار می رود نیروي پسا است که ضریب
پسا را به همراه دارد ; ضریب پسایی که در اینجا بکار برده می شود ،براي سیستم هاي گاز مایع است ، سیستم
هایی که در آن حباب گاز و مایع که معمولا آب است ،در سطح جدایشی با هم تماس دارند و لغزشی در این سطح
به بار می آید که نیروي پسا را به دنبال دارد . از جمله مختصاتی که براي محاسبات به کار گرفته می شود ، اویلر
– اویلري ، اویلر - لاگرانژي و . . . است که مختصات مورد بررسی ما اویلر – اویلري است . معادلاتی که در کاوش
به کار برده شده است براي سیالات نیوتنی است که معمولا براي سینی هاي غربالی و . . . CFD هاي گوناگون
بکار برده شده است . در این پژوهش مروري می کنیم بر ضرائب پسایی که در این چارچوب و در طی سالیان دور
توسط پژوهشگران بدست آمده اند .
روي آن کار کرده اند تا بتوانند یا این مشکل را بصورت کلی حل یا حل آن را چند قدم
جلوتر ببرند که ما نیز در این مقاله یک راه کار جدید را ارائه کرده ایم تا بتوانیم حل این
مسائله را به حل کامل نزدیک کرده و در راهکار جدید ما سه مشکل اصلی پیش روي
مسیر فروشنده دوره گرد یعنی بن بست، تقاطع و مسیر هاي بحرانی را تشخیص و اقدام
به رفع آنها کنید و در نهایت مسیري را که براي فروشنده ارائه می دهد یک مسیري که
خالی از سه مشکل بالاست، می باشد و نتایج شبیه سازي راهکار جدید نیز نشان دهنده
این است که راهکار ما توانسته است نسبت به راهکارهاي گذشته برتري داشته باشد که
همه این ها از مزایاي راهکار نو ما است.
در بخش کشاورزي محسوب می شود. آستانه تحمل گیاهان در رابطه با پارامتر هاي هواشناسی محدود است و در
دامنه گرمایی مشخصی قابلیت رشد و فعایت زیستی دارد.. هر ناهنجاري بر این پارامتر ها به صورت مستقیم و غیر
مستقیم بر تولیدات کشاورزي اثرات زیادي دارد. عوامل تنش زا باعث تغییر و اختلال در فرآیند هاي فیزیولوژیکی
می شودو به این گونه تولید گیاهان زراعی را تحت تاثیر قرار می دهد. تنش سرما از عوامل محیطی است سبب
کاهش عملکرد محصولات در کشت پاییزه در مناطق نیمه گرمسیري می شود. آسیب هاي ناشی از سرمازدگی به
محصولات زراعی بسته به رقم و گونه مختلف است. این عمل ناشی از سرمازدگی زودرس پاییزه است. براي هر
رقم نه تنها درجه حرارت مطلوب است بلکه فعالیت رشد و فعالیت هاي گوناگون گیاهان داراي فعالیت هاي ایده
آل محدوده حرارتی کشنده و کمینه و بیشینه است. کاهش دما از آستانه تحمل کمینه گیاه خسارت زا باشد.
development of plants. And are considered as controllable, effective and agricultural
variables. Plant tolerance thresholds are limited in relation to each of the
meteorological parameters and have the ability to grow and develop biological
activity in a certain heat range, and any anomaly on these parameters can have direct
and indirect effects on agricultural production. Stressors alter and disrupt the
physiological processes of plants. And from this change, they affect the production
of crops. Cold stress is one of the most important environmental factors that reduces
the yield of crops in autumn crops in subtropical regions. The damage caused by
frost to crops varies depending on the species and cultivar. And this action is often
caused by autumn frosts. For any part of Qom, not only there is a favorable
temperature, but also the growth stages and various activities of plants, with ideal
temperatures as well as lethal temperature range and minimum and maximum,
reducing the temperature of The minimum plant tolerance threshold can be harmful.
of fluids is examined in various ways; For these fluids, equations are considered that
are specific to the fluid and its single-phase, biphasic and multi-phase. One of the
equations used in these methods is the drag force which has a drag coefficient; The
drag coefficient used here is for liquefied gas systems, systems in which the gas
bubble and the liquid, which is usually water, come into contact at the separation
surface and a slip occurs at this level, which is the drag force. To follow. Among the
coordinates used for calculations, Euler-Euler, Euler-Lagrange and etc. The
coordinates we are considering are Euler-Eulerian. The equations used in various
CFD probes are for Newtonian fluids, usually for sieve trays and etc Used. In this
study, we review the drag coefficients that have been obtained by researchers in this
framework over the years.
have worked on so that they can either solve this problem in general or take it a
few steps further. In this article, we also present a new solution. In order to be able
to solve this problem close to a complete solution, and in our new solution, it
identifies and solves the three main problems facing the traveling salesman route,
namely deadlock, intersection and critical routes, and finally the route for The
vendor offers a path that is free of the above three problems, and the simulation
results of the new solution also show that our solution has been able to be superior
to previous solutions, all of which are the advantages of our new solution.
سپس هر کدام از این دو مقوله را تع ریف کرده معادلات موازنه جمعیت ذرات را در بخش های مختلف شرح داده
تغییرات اندازه ذرات را با گذشت زمان نشان میدهیم، در مورد لایه مضاعف الکتریکی بحث می کنیم فرآیندهای
مختلف ذرات مانند پیدایش، تجمع مرگ، متلاشی شدن، توده دارشدن، هسته دار شدن، شکست، چگونگی
کوچک و بزرگ شدن ذرات و معادلات موازنه ذرات در محیط های گاز، مایع و جامد را بررسی می نماییم. تعادل
جمعیت ذرات در بخش بررسی می شوند. بررسی موازنه جمعیت ذرات کاری بهینه در صنعت و تولید کودهای
شیمیایی و غیره است.
مورد بررسی قرار می گیرد ; براي این سیالات معادلاتی در نظر گرفته می شود که ویژه آن سیال و یک فازي ، دو
فازي و چند فازي بودن آن است . از جمله معادلاتی که در این روش ها بکار می رود نیروي پسا است که ضریب
پسا را به همراه دارد ; ضریب پسایی که در اینجا بکار برده می شود ،براي سیستم هاي گاز مایع است ، سیستم
هایی که در آن حباب گاز و مایع که معمولا آب است ،در سطح جدایشی با هم تماس دارند و لغزشی در این سطح
به بار می آید که نیروي پسا را به دنبال دارد . از جمله مختصاتی که براي محاسبات به کار گرفته می شود ، اویلر
– اویلري ، اویلر - لاگرانژي و . . . است که مختصات مورد بررسی ما اویلر – اویلري است . معادلاتی که در کاوش
به کار برده شده است براي سیالات نیوتنی است که معمولا براي سینی هاي غربالی و . . . CFD هاي گوناگون
بکار برده شده است . در این پژوهش مروري می کنیم بر ضرائب پسایی که در این چارچوب و در طی سالیان دور
توسط پژوهشگران بدست آمده اند .
روي آن کار کرده اند تا بتوانند یا این مشکل را بصورت کلی حل یا حل آن را چند قدم
جلوتر ببرند که ما نیز در این مقاله یک راه کار جدید را ارائه کرده ایم تا بتوانیم حل این
مسائله را به حل کامل نزدیک کرده و در راهکار جدید ما سه مشکل اصلی پیش روي
مسیر فروشنده دوره گرد یعنی بن بست، تقاطع و مسیر هاي بحرانی را تشخیص و اقدام
به رفع آنها کنید و در نهایت مسیري را که براي فروشنده ارائه می دهد یک مسیري که
خالی از سه مشکل بالاست، می باشد و نتایج شبیه سازي راهکار جدید نیز نشان دهنده
این است که راهکار ما توانسته است نسبت به راهکارهاي گذشته برتري داشته باشد که
همه این ها از مزایاي راهکار نو ما است.
در بخش کشاورزي محسوب می شود. آستانه تحمل گیاهان در رابطه با پارامتر هاي هواشناسی محدود است و در
دامنه گرمایی مشخصی قابلیت رشد و فعایت زیستی دارد.. هر ناهنجاري بر این پارامتر ها به صورت مستقیم و غیر
مستقیم بر تولیدات کشاورزي اثرات زیادي دارد. عوامل تنش زا باعث تغییر و اختلال در فرآیند هاي فیزیولوژیکی
می شودو به این گونه تولید گیاهان زراعی را تحت تاثیر قرار می دهد. تنش سرما از عوامل محیطی است سبب
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