Mechanical and Automotive Engineering

In this paper, based on Woodward model , an analytical model has been developed for perforation of projectile into ceramic co mposites targets. In the new model, contribution of different phases of projectile during perforation (erosion, mushrooming and rigid phase), modificat ion of semi-angle of ceramic cone during perforation process, modification of the shape of the nose of projectile and changes in yield strength of ceramic during perforation are considered. The ballistic limit and residual velocity of projectile by presented model have a good agreement with experimental and other theoretical results of other researchers.

This paper looks into the developments and simulation of electric vehicles (EV) and hybrid electric vehicles (HEV) powertrains. The investigation is compassed through ADVISOR software (Advanced Vehicle Simulator), correlated to the selected country energy consumption, whereas this project is aimed at Iran's energy sources to be observed on the assumption of HEV vehicles suitability for this country energy consumptions. In addition to this research, the carbon footprint of Iran's energy sources has been carried out, to select the most efficient source, and to simulate an exceptional powertrain to examine the progress of the main components (e.g. electric motor, battery) of the vehicle construction through its efficiency, and pollution. Further to this test the structures of the components is simulated and compared with other selected powertrains through Simulink and ADVISOR. As a result, the Energy Usage (Power & Regen Mode), Fuel Economy, Emission, and overall system Efficiency, has been analysed.

Demand for air conditioners is steadily increasing due to global warming and improved living standards. The noise, as well as the performance of air conditioners, are recognized as one of the crucial factors that determine the air conditioners' values. The performance and noise of the air conditioner are mostly determined by those of its outdoor unit, which in turn depend on those of the cooling fan unit. Therefore, a cooling fan unit of high-performance and low noise is essential for air-conditioner manufacturers and developers. In this paper, the flow performance and flow noise of the entire outdoor unit with an axial cooling fan in a split-type air-conditioner were investigated. First, a virtual fan tester constructed by using about 18 million grids is developed for highly resolved flow simulation. The unsteady Reynolds-Averaged Navier-Stokes equations are numerically solved by using finite-volume computational fluid dynamics techniques. To verify the validity of the numerical analysis, the predicted P-Q curve of the cooling fan in a full outdoor unit is compared with the measured one. There was an excellent agreement between the two curves. The further detailed analysis identifies the coherent vortex structures between the fan blade tip and fan orifice, which adversely affect the flow performance and causes flow noise. Based on this analysis, the optimization of fan orifice was carried out using the response surface method with three geometric parameters: inlet radius, neck length, and outlet angel of the orifice. The optimum layout for the high flow rate is proposed under the understanding that the increased flow rate can be converted to noise reduction. The additional computation using the proposed optimum orifice shows that the flow rate is increased by 4.6% at the operating point. Finally, the engineering sample was manufactured by using the optimum design, and the measured data confirmed that the flow rate were increased by 2.1%, the noise reduction was made by 2.8 dBA, and the power consumption is reduced by 4.0% at the operating rotational speed.