并联型TBCC推进系统变维度一体化数值模拟方法研究

An Investigation of Multi-Fidelity Coupling Simulation of over/ under Turbine-Based Combined-Cycle Propulsion System

关键词:  TBCC推进系统  内外流一体化  变维度数值仿真  涡轮发动机模型  准一维冲压发动机模型

Key words:  Turbine-based combined-cycle propulsion system  External and internal flow  Multi-fidelity numerical simulation  Turbine engine model  Quasi-one-dimensional ramjet model

摘要:

为了缩短组合动力系统内外流一体化数值仿真时间，加快高超声速飞行器的研制进度，基于商业软件发展了一种飞行器进/排气系统多维仿真与发动机等效一维模型相结合的TBCC推进系统变维度一体化数值仿真方法，其中进/排气系统采用多维数值仿真，涡轮发动机采用部件特性的数学模型，冲压发动机采用准一维数学模型，结合商业软件通过边界条件调用，实现变维度一体化数值仿真。数值仿真对比分析表明：TBCC推进系统等效一维模型模拟结果与GasTurb 10和风洞试验结果变化规律一致吻合较好，误差不大于3.0%；采用变维度数值模拟方法对某TBCC推进系统沿飞行轨迹加速爬升过程的分析表明，进气道总收缩比从2.0增大到5.5，喷管面积比从1.2增大到7.8。涡轮模态时，TBCC喷管出现明显过膨胀现象；冲压模态时，喷管的落压比随马赫数增大从8.3逐渐增大至20.4，过膨胀现象减弱，从而验证了多维与一维耦合数值仿真方法的可行性。

Abstract:

To reduce the numerical simulation time for combined cycle propulsion system external and internal flow and accelerate the development of hypersonic vehicle，a multi-fidelity simulation method used to simulate external flow including inlet and nozzle systems and internal flow including engine models of turbine-based combined-cycle （TBCC） propulsion systems was developed based on commercial software. The inlet and nozzle of TBCC propulsion systems were calculated through multi-dimensional method. While， turbine engine was modeled based on component characteristic maps and ramjet engine was modeled through quasi-one-dimensional flow theory. These engine models were implemented into commercial software through secondary development of boundary conditions. TBCC propulsion system models were verified with GasTurb 10 and experiment data from wind tunnel tests. The results indicated that the turbine and ramjet model agreed well with previous results with deviation smaller than 3.0%. Then， this multi-fidelity simulation method was applied to the simulation of a TBCC propulsion system along a specific flight trajectory. The contraction ratio of inlet and expansion ratio of nozzle along the flight trajectory increased from 2.0 to 5.5 and 1.2 to 7.8， respectively. During turbine mode TBCC nozzle was over-expansion. While， at ramjet mode nozzle over-expansion was mitigated due to nozzle pressure ratio increased from 8.3 to 20.4 with increasing inflow Mach number. These results verify the feasibility of multi-fidelity simulation method developed in this paper.