基于混合维度仿真的自适应循环发动机引射喷管安装性能研究

Installed Performance of Adaptive Cycle Engine Ejector Nozzle Based on Multi-Fidelity Simulation

关键词:  自适应循环发动机  混合维度仿真  计算流体动力学  引射喷管  后体阻力  变可信度代理模型

Key words:  Adaptive cycle engine  Multi-fidelity simulation  Computational fluid dynamics  Ejector nozzle  Afterbody drag  Variable-fidelity surrogate model

摘要:

自适应循环发动机（Adaptive Cycle Engine，简称ACE）独特的三外涵道结构使引射喷管成为一种可行的排气系统方案。为准确评估各种工况下引射喷管与ACE匹配工作下的安装性能，提出了一种基于变可信度代理模型的ACE-引射喷管混合维度仿真方法。该方法搭配引射喷管高、低两种可信度的计算流体动力学（Computational Fluid Dynamics，简称CFD）仿真模型，建立了引射喷管变可信度代理模型。通过动态更新该代理模型，在引射喷管性能空间的匹配工作区域集中进行高可信度CFD仿真，高效准确地实现了引射喷管匹配状态下的安装性能评估。仿真结果发现，ACE引射喷管在亚声速巡航和超声速巡航状态下的安装推力系数分别为0.979和0.961，在跨声速区段采用中间状态加速时后体阻力系数达到最大，为0.25。亚声速巡航状态下主喷管流量系数最低，为0.896。应用本方法仅需180次低可信度CFD仿真以及173次高可信度CFD仿真即可完成共计33个ACE工作点的引射喷管安装性能计算。

Abstract:

The unique three-bypasses configuration of the Adaptive Cycle Engine （ACE） makes the ejector nozzle a viable exhaust system option. To accurately evaluate the installed performance of the ejector nozzle matching with ACE under various operating conditions， an ACE-ejector nozzle multi-fidelity simulation method was proposed based on the variable-fidelity surrogate model. A variable-fidelity surrogate model of ejector nozzle was established through the combination of ejector nozzle low-fidelity and high-fidelity computational fluid dynamics （CFD） model. By dynamically optimizing and updating the variable-fidelity surrogate model， high-fidelity CFD simulations are carried out in the matching region of the ejector nozzle performance space， and the performance evaluation of the ejector nozzle in the matching state is efficiently achieved. Simulation results show that the installed thrust coefficients of the ACE ejector nozzle are 0.979 and 0.961 respectively at subsonic and supersonic cruise. The afterbody drag coefficient reaches a maximum of 0.25 in the transonic speed region at dry acceleration condition. The primary nozzle discharge coefficient is the lowest at subsonic cruise， which is 0.896. Through the method， only 180 low-fidelity CFD simulations and 173 high-fidelity CFD simulations are required to complete the ejector nozzle installed performance evaluation of 33 ACE operating points.