A new simulation strategy is proposed for the starting process of missile turbojet engine windmill. The starting process of windmill before ignition is simulated using a radial basis function neural network (RBFNN) , ...A new simulation strategy is proposed for the starting process of missile turbojet engine windmill. The starting process of windmill before ignition is simulated using a radial basis function neural network (RBFNN) , and the acceleration process after ignition which model is a set of nonlinear equations is solved using a particle swarm optimization (PSO) algorithm. The introduction of PSO helped to tackle the problem of divergence caused by traditional iteration methods. The calculated result is in a great agreement with test data, which shows that the presented model has a high accuracy. The starting processes are simulated at different ignition times, and the results are analyzed synthetically. The analysis shows how the ignition time affects the starting performance of engine windmill. The method offers a useful tool for ignition time optimization as well as engine starting performance analysis.展开更多
The problem of analysis and synthesis of robust control is addressed in this work. The approach transferring the robust control design into Linear Matrix Inequality (LMI) is provided. The LMI standard structure of rob...The problem of analysis and synthesis of robust control is addressed in this work. The approach transferring the robust control design into Linear Matrix Inequality (LMI) is provided. The LMI standard structure of robust controller is also given and the controller is obtained through solving three LMIs. As an example, a robust control law is designed to the twin-spool turbojet engine system using the given approach. The result shows that LMI approach is feasible.展开更多
Gas-turbines are widely used to power aero planes because they are light,compact with a high power-to-weight ratio.In the turbo jet engine,the main operating variables are:compressor pressure ratio rp and turbine inle...Gas-turbines are widely used to power aero planes because they are light,compact with a high power-to-weight ratio.In the turbo jet engine,the main operating variables are:compressor pressure ratio rp and turbine inlet temperature(TIT).These variables affect the specific thrust and specific fuel consumption(SFC),which represent the main performance parameters.In addition to the analytical work,a computer program of the General Algebraic Modeling System(GAMS)was used for analysis and optimization.The analysis shows that the specific thrust strongly depends on turbine inlet temperature(TIT),where a 10%decrease in TIT results in 6.7%decrease in specific thrust and 6.8%decrease in SFC.Furthermore,the value of optimum pressure ratio rf for maximum specific thrust increases with TIT.A 10%decrease from design TIT results in 11.43%decrease in rf.The value of optimum pressure ratio for the turbojet engine operating at Ma=0.8 and altitude Alt=13000 m,and TIT=1700 K was found to be 14.&2015 National Laboratory for Aeronautics and Astronautics.Production and hosting by Elsevier B.V.展开更多
基金Sponsored by the National Aeronautical Science Foundation of China(20095584006)
文摘A new simulation strategy is proposed for the starting process of missile turbojet engine windmill. The starting process of windmill before ignition is simulated using a radial basis function neural network (RBFNN) , and the acceleration process after ignition which model is a set of nonlinear equations is solved using a particle swarm optimization (PSO) algorithm. The introduction of PSO helped to tackle the problem of divergence caused by traditional iteration methods. The calculated result is in a great agreement with test data, which shows that the presented model has a high accuracy. The starting processes are simulated at different ignition times, and the results are analyzed synthetically. The analysis shows how the ignition time affects the starting performance of engine windmill. The method offers a useful tool for ignition time optimization as well as engine starting performance analysis.
基金National Natural Science Foundation of China! ( 6 98740 3 2 )The Youth Teacher Foundation of NPU
文摘The problem of analysis and synthesis of robust control is addressed in this work. The approach transferring the robust control design into Linear Matrix Inequality (LMI) is provided. The LMI standard structure of robust controller is also given and the controller is obtained through solving three LMIs. As an example, a robust control law is designed to the twin-spool turbojet engine system using the given approach. The result shows that LMI approach is feasible.
文摘Gas-turbines are widely used to power aero planes because they are light,compact with a high power-to-weight ratio.In the turbo jet engine,the main operating variables are:compressor pressure ratio rp and turbine inlet temperature(TIT).These variables affect the specific thrust and specific fuel consumption(SFC),which represent the main performance parameters.In addition to the analytical work,a computer program of the General Algebraic Modeling System(GAMS)was used for analysis and optimization.The analysis shows that the specific thrust strongly depends on turbine inlet temperature(TIT),where a 10%decrease in TIT results in 6.7%decrease in specific thrust and 6.8%decrease in SFC.Furthermore,the value of optimum pressure ratio rf for maximum specific thrust increases with TIT.A 10%decrease from design TIT results in 11.43%decrease in rf.The value of optimum pressure ratio for the turbojet engine operating at Ma=0.8 and altitude Alt=13000 m,and TIT=1700 K was found to be 14.&2015 National Laboratory for Aeronautics and Astronautics.Production and hosting by Elsevier B.V.
