The sub-critical combustion case, RCM-2, was simulated with both heterogeneous and homogeneous sp... more The sub-critical combustion case, RCM-2, was simulated with both heterogeneous and homogeneous spray combustion models. The MASCOTTE test data should be better than any which have been previously used to tune the several parameters in these models. It is unreasonable to expect that spray flames, even of hydrogen and oxygen, can be accurately predicted without extensive model validation with test data representative of the conditions which exists in rocket engine combustion chambers. Even global data such as chamber pressure and thrust have not been obtained for single coaxial element combustor flows. The IWRCM data provide a good starting point, but no CFD model tuning has yet been attempted for such experiments. Direct comparisons of predictions to test data at this point will not establish which of several modeling techniques is best.
44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2008
Computational models have been developed and demonstrated effectively in solid rocket motor and l... more Computational models have been developed and demonstrated effectively in solid rocket motor and launch vehicle design analysis and problem diagnostics applications. Most solid rocket motors utilize ablative carbon-carbon composite materials for nozzle cooling the protection. One ...
A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated ... more A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated internal flowfield of the SRM (solid rocket motor) to explore the impacts due to the effects of chemical reaction, particle dynamics, and slag accumulation on the solid rocket motor (SRM). The particulate multi-phase flowfield with chemical reaction, particle evaporation, combustion, breakup, and agglomeration models are included in present study to obtain a better understanding of the SRM design. Finite rate chemistry model is applied to simulate the chemical reaction effects. Hermsen correlation model is used for the combustion simulation. The evaporation model introduced by Spalding is utilized to include the heat transfer from the particulate phase to the gase phase due to the evaporation of the particles. A correlation of the minimum particle size for breakup expressed in terms of the Al/Al2O3 surface tension and shear force was employed to simulate the breakup of particles. It is a...
A CFD model is developed for the analysis of reacting and nonreacting film cooling supersonic flo... more A CFD model is developed for the analysis of reacting and nonreacting film cooling supersonic flows. The present study demonstrates the effectiveness of using an extended two-equation turbulence model with compressibility corrections for supersonic shear-layer simulations. An efficient finite-rate chemistry solution method is employed for effective simulation of stiff chemistry systems. Two-dimensional supersonic film cooling test cases with and without chemical reaction are investigated for the validation of the present model. The underlying fluid dynamics solver is a predictor as well as a multicorrector, pressure-based Navier-Stokes flow solver.
Current design of high performance turbopumps for rocket engines requires effective and robust an... more Current design of high performance turbopumps for rocket engines requires effective and robust analytical tools to provide design information in a productive manner. The main goal of this study is to develop a robust and effective computational fluid dynamics (CFD) pump model for general turbopump design and analysis applications. A finite gifference Navier~tokes flow solver, FDNS, which includes an extended k-e turbulence model and appropriate moving zonal interface boundary conditions, was developed to analyze turbulent flows in turbomachinery devices. In the present study, two key components of the turbopump, the inducer and impeller, were investigated by the proposed pump model, and the numerical results were benchmarked by the experimental data provided by Rocketdyne.
A computational plasma aerodynamics model is developed to study the performance of a laser propel... more A computational plasma aerodynamics model is developed to study the performance of a laser propelled Lightcraft. The computational methodology is based on a time-accurate, three-dimensional, finite-difference, chemically reacting, unstructured grid, pressure-based formulation. The underlying physics are added and tested systematically using a building-block approach. The physics modeled include non-equilibrium thermodynamics, non-equilibrium air-plasma finite-rate kinetics, specular ray tracing, laser beam energy absorption and refraction by plasma, non-equilibrium plasma radiation, and plasma resonance. A series of transient computations are performed at several laser pulse energy levels and the simulated physics are discussed and compared with those of tests and literatures. The predicted coupling coefficients for the Lightcraft compared reasonably well with those of tests conducted on a pendulum apparatus.
45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2009
Scramjet propulsion provides promising opportunities for high speed transportation and cost reduc... more Scramjet propulsion provides promising opportunities for high speed transportation and cost reduction for satellite and spacecraft launch operations. Recent successes in flight demonstrations of Mach 7 to 10 flight speeds of the HyShot and Hyper-X programs have in part attributed ...
Flow distribution within the Space Shuttle Main Engine (SSME) main injector assembly has a profou... more Flow distribution within the Space Shuttle Main Engine (SSME) main injector assembly has a profound effect on both the performance and the hardware integrity of the main combustion chamber. In order to predict the flow distribution within the main injector assembly, a three-dimensional computational fluid dynamics (CFD) model capable of computing the propellant flows from the transfer ducts and inlet dome, through the injector assembly, to the injector faceplate of the main combustion chamber, is developed and an analysis for a test engine of the Phase II+ configuration is conducted. The CFD model is a pressure-based viscous flow formulation. Porosity concept is employed to depict the effects of blockage and drag force caused by the presence of the Liquid Oxidizer (LOX) post forest in the injector assembly. Expressions of drag coefficients over a wide range of Reynolds numbers are deduced based on studies of flow over tube banks. Numerical results indicated that the mixture ratio at downstream of the injector face could be near stoichiometric around baffle elements during off-design conditions. Nomenclature global Oow exit area local Oow exit area turbulence modeling constant turbulence modeling constant • Research Engineer, Member AIAA. t President, Memt?er AIAA.
The sub-critical combustion case, RCM-2, was simulated with both heterogeneous and homogeneous sp... more The sub-critical combustion case, RCM-2, was simulated with both heterogeneous and homogeneous spray combustion models. The MASCOTTE test data should be better than any which have been previously used to tune the several parameters in these models. It is unreasonable to expect that spray flames, even of hydrogen and oxygen, can be accurately predicted without extensive model validation with test data representative of the conditions which exists in rocket engine combustion chambers. Even global data such as chamber pressure and thrust have not been obtained for single coaxial element combustor flows. The IWRCM data provide a good starting point, but no CFD model tuning has yet been attempted for such experiments. Direct comparisons of predictions to test data at this point will not establish which of several modeling techniques is best.
44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2008
Computational models have been developed and demonstrated effectively in solid rocket motor and l... more Computational models have been developed and demonstrated effectively in solid rocket motor and launch vehicle design analysis and problem diagnostics applications. Most solid rocket motors utilize ablative carbon-carbon composite materials for nozzle cooling the protection. One ...
A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated ... more A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated internal flowfield of the SRM (solid rocket motor) to explore the impacts due to the effects of chemical reaction, particle dynamics, and slag accumulation on the solid rocket motor (SRM). The particulate multi-phase flowfield with chemical reaction, particle evaporation, combustion, breakup, and agglomeration models are included in present study to obtain a better understanding of the SRM design. Finite rate chemistry model is applied to simulate the chemical reaction effects. Hermsen correlation model is used for the combustion simulation. The evaporation model introduced by Spalding is utilized to include the heat transfer from the particulate phase to the gase phase due to the evaporation of the particles. A correlation of the minimum particle size for breakup expressed in terms of the Al/Al2O3 surface tension and shear force was employed to simulate the breakup of particles. It is a...
A CFD model is developed for the analysis of reacting and nonreacting film cooling supersonic flo... more A CFD model is developed for the analysis of reacting and nonreacting film cooling supersonic flows. The present study demonstrates the effectiveness of using an extended two-equation turbulence model with compressibility corrections for supersonic shear-layer simulations. An efficient finite-rate chemistry solution method is employed for effective simulation of stiff chemistry systems. Two-dimensional supersonic film cooling test cases with and without chemical reaction are investigated for the validation of the present model. The underlying fluid dynamics solver is a predictor as well as a multicorrector, pressure-based Navier-Stokes flow solver.
Current design of high performance turbopumps for rocket engines requires effective and robust an... more Current design of high performance turbopumps for rocket engines requires effective and robust analytical tools to provide design information in a productive manner. The main goal of this study is to develop a robust and effective computational fluid dynamics (CFD) pump model for general turbopump design and analysis applications. A finite gifference Navier~tokes flow solver, FDNS, which includes an extended k-e turbulence model and appropriate moving zonal interface boundary conditions, was developed to analyze turbulent flows in turbomachinery devices. In the present study, two key components of the turbopump, the inducer and impeller, were investigated by the proposed pump model, and the numerical results were benchmarked by the experimental data provided by Rocketdyne.
A computational plasma aerodynamics model is developed to study the performance of a laser propel... more A computational plasma aerodynamics model is developed to study the performance of a laser propelled Lightcraft. The computational methodology is based on a time-accurate, three-dimensional, finite-difference, chemically reacting, unstructured grid, pressure-based formulation. The underlying physics are added and tested systematically using a building-block approach. The physics modeled include non-equilibrium thermodynamics, non-equilibrium air-plasma finite-rate kinetics, specular ray tracing, laser beam energy absorption and refraction by plasma, non-equilibrium plasma radiation, and plasma resonance. A series of transient computations are performed at several laser pulse energy levels and the simulated physics are discussed and compared with those of tests and literatures. The predicted coupling coefficients for the Lightcraft compared reasonably well with those of tests conducted on a pendulum apparatus.
45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2009
Scramjet propulsion provides promising opportunities for high speed transportation and cost reduc... more Scramjet propulsion provides promising opportunities for high speed transportation and cost reduction for satellite and spacecraft launch operations. Recent successes in flight demonstrations of Mach 7 to 10 flight speeds of the HyShot and Hyper-X programs have in part attributed ...
Flow distribution within the Space Shuttle Main Engine (SSME) main injector assembly has a profou... more Flow distribution within the Space Shuttle Main Engine (SSME) main injector assembly has a profound effect on both the performance and the hardware integrity of the main combustion chamber. In order to predict the flow distribution within the main injector assembly, a three-dimensional computational fluid dynamics (CFD) model capable of computing the propellant flows from the transfer ducts and inlet dome, through the injector assembly, to the injector faceplate of the main combustion chamber, is developed and an analysis for a test engine of the Phase II+ configuration is conducted. The CFD model is a pressure-based viscous flow formulation. Porosity concept is employed to depict the effects of blockage and drag force caused by the presence of the Liquid Oxidizer (LOX) post forest in the injector assembly. Expressions of drag coefficients over a wide range of Reynolds numbers are deduced based on studies of flow over tube banks. Numerical results indicated that the mixture ratio at downstream of the injector face could be near stoichiometric around baffle elements during off-design conditions. Nomenclature global Oow exit area local Oow exit area turbulence modeling constant turbulence modeling constant • Research Engineer, Member AIAA. t President, Memt?er AIAA.
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Papers by Yen-Sen Chen