Multi-Objective Design Optimization of Linear Aerospike Engine
Multi-Objective Design Optimization of Linear Aerospike Engine
复制标题
线性气动塞式发动机多目标设计优化
DOI：
10.11394/tjpnsec.9.61
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
藤川貴弘，照井勇輔，渡邉真也，米本浩一
中科院分区：
文献类型：
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作者：
浅野俊幸;廣川雄一;西川憲明;丹羽雄輔;藤川貴弘，照井勇輔，渡邉真也，米本浩一
线性塞式发动机是由一组小单元发动机和一个一侧向大气开放的大型塞式喷管组成的火箭发动机。它是未来空间运输的有前途的推进系统之一，因为它可以在广泛的环境压力条件下实现高性能。尽管塞式发动机具有这一优点，但以往对塞式喷管形状的设计研究仅致力于在单个设计点处使性能最大化。为探索塞式发动机多高度性能的设计方法，对塞式发动机进行了多目标优化设计。设计变量定义了单元发动机参数和喷管形状，喷管参数化采用单调三次样条函数。结合单元发动机化学平衡计算、壁面流动Riemann解算和底部流动理论模型，建立了发动机工程级性能分析模型。五个目标函数被认为是在三个工作高度的比冲最大化，最小化的锥喷管弧长，和最小化的总发动机高度。采用MOEA/D方法，通过对聚集函数的动态控制，得到了收敛性好、分布广的非支配解。在这些解决方案中，观察到与通过先前方法设计的形状不同的尖峰喷嘴形状。通过对典型解的详细考察，用平行坐标图揭示了上级解中目标函数与设计变量之间的关系。
Linear aerospike engine is a rocket engine that is composed of arrays of small cell engines and a large spike nozzle whose one side is open to atmosphere. It is one of the promising propulsion systems for future space transportation since it can realize high performance for a wide range of ambient pressure conditions. Despite this advantage of the aerospike engine, previous design studies on aerospike nozzle shape are only devoted to maximizing the performance at a single design point. In order to explore the design of the aerospike engine considering performance at multiple operating altitudes, multi-objective design optimization is conducted in this paper. Design variables define cell engine parameters and the shape of the spike nozzle whose parameterization is carried out using monotonic cubic spline. An engineering-level performance analysis model of the engine is developed by combining 1) chemical equilibrium calculation for cell engines, 2) Riemann solver for spike wall flow, and 3) theoretical model for spike base flow. Five objective functions are considered for the maximization of specific impulse at three operating altitudes, the minimization of spike nozzle arc length, and the minimization of total engine height. The formulated many-objective problem is solved via MOEA/D with dynamic control of aggregate functions, and well-converged and widely-spread nondominated solutions are obtained. In these solutions, spike nozzle shapes that are different from shapes designed by previous methods are observed. After representative solutions are inspected in detail, the relations between objective functions and design variables in superior solutions are revealed using parallel coordinates plots.