Numerical simulation of transpiration cooling over blunt bodies at hypersonic Mach numbers

1995 ◽  
Author(s):  
Mr Sreekanth ◽  
N Reddy
Keyword(s):  
Numerical Simulation ◽  
Transpiration Cooling ◽  
Blunt Bodies ◽  
Mach Numbers

Computational study of unsteady gas flow in the combustion chamber of a ramjet engine with heat transfer

2021 ◽  
pp. 50-61
Author(s):  
Надежда Петровна Скибина
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Supersonic Flow ◽  
Combustion Chamber ◽  
Gas Flow ◽  
Stokes Equations ◽  
Heat Conducting ◽  
Measuring Device ◽  
Ramjet Engine ◽  
Mach Numbers

Проведено численное исследование нестационарного турбулентного сверхзвукового течения в камере сгорания прямоточного воздушно-реактивного двигателя. Описана методика экспериментального измерения температуры на стенке осесимметричного канала в камере сгорания двигателя. Математическое моделирование обтекания исследуемой модели двигателя проводилось для скоростей набегающего потока M = 5 ... 7. Начальные и граничные условия задачи соответствовали реальному аэродинамическому эксперименту. Проанализированы результаты численного расчета. Рассмотрено изменение распределения температуры вдоль стенки канала с течением времени. Проведена оценка согласованности полученных экспериментальных данных с результатами математического моделирования. Purpose. The aim of this study is a numerical simulation of unsteady supersonic gas flow in a working path of ramjet engine under conditions identical to aerodynamic tests. Free stream velocity corresponding to Mach numbers M=5 ... 7 are considered. Methodology. Presented study addresses the methods of physical and numerical simulation. The probing device for thermometric that allows to recording the temperature values along the wall of internal duct was proposed. To describe the motion of a viscous heat-conducting gas the unsteady Reynolds averaged Navier - Stokes equations are considered. The flow turbulence is accounted by the modified SST model. The problem was solved in ANSYS Fluent using finite-volume method. The initial and boundary conditions for unsteady calculation are set according to conditions of real aerodynamic tests. The coupled heat transfer for supersonic flow and elements of ramjet engine model are realized by setting of thermophysical properties of materials. The reliability testing of numerical simulation has been made to compare the results of calculations and the data of thermometric experimental tests. Findings. Numerical simulation of aerodynamic tests for ramjet engine was carried out. The agreement between the results of numerical calculations and experimental measurements for the velocity in the channel under consideration was obtained; the error was shown to be 2%. The temperature values were obtained in the area of contact of the supersonic flow with the surface of the measuring device for the external incident flow velocities for Mach numbers M = 5 ... 7. The process of heating the material in the channel that simulated the section of the engine combustion chamber was analyzed. The temperature distribution was studied depending on the position of the material layer under consideration relative to the contact zone with the flow. Value. In the course of the work, the fields of flow around the model of a ramjet engine were obtained, including the region of supersonic flow in the inner part of axisymmetric channel. The analysis of the temperature fields showed that to improve the quality of the results, it is necessary to take into account the depth of the calorimetric sensor. The obtained results will be used to estimate the time of interaction of the supersonic flow with the fuel surface required to reach the combustion temperature.

Study on Micro-Turbine Engine’s Characteristics During Windmill Starting Process

2012 ◽  
Author(s):  
Xin Fu ◽  
Zhaoyun Wan ◽  
Guoping Huang ◽  
Zheng Xie
Keyword(s):  
Numerical Simulation ◽  
Ignition Time ◽  
Jet Fuel ◽  
Mechanical Loss ◽  
Jet Engine ◽  
Rotation Rates ◽  
Chamber Temperature ◽  
Mach Numbers ◽  
Micro Turbine ◽  
Starting Process

This paper examines the performance characteristics of a certain model of micro-turbine jet engine during windmill starting process, on the basis of numerical simulation and experimentation. First, the rotor’s comprehensive mechanical loss at various rotation rates below idling speed can be generated through the combination of the cold blowing experiments on turbine-less rotor system and the numerical simulation upon compressor under related in-flow Mach numbers. Given the rotor’s comprehensive mechanical loss, cold blowing experiments on the whole micro-turbine jet engine bring out the whole engine’s balance characteristics at various Mach numbers below idling speed, via the numerical simulation upon compressor and turbine. Moreover, based on numerical simulation and experimentation, the influence of propane ignition time and propane pressure upon engine rotation speed and combustion chamber temperature is studied to meet the demand of combustion in the shortest possible time, as well as confirm the minimum required propane. Further experiments show the optimal jet fuel supply time and pattern that bring the micro-turbine jet engine to idling status within the minimum time, and also reveal the minimum windmill starting time at various in-flow Mach numbers, as well as the minimum Mach number for windmill start.

Numerical Simulation of Shock Bubble Interaction with Different Mach Numbers

2015 ◽  
Vol 32 (3) ◽  
pp. 034701 ◽  
Author(s):  
Jie Yang ◽  
Zhen-Hua Wan ◽  
Bo-Fu Wang ◽  
De-Jun Sun
Keyword(s):  
Numerical Simulation ◽  
Bubble Interaction ◽  
Mach Numbers
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