Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2018-01-02 Cooperative journals: 《工程热物理学报》
Abstract: At present, the characteristic line method and the optimization method based on the CFD analysis arethe mainly methods for hypersonic nozzles designing. However, the characteristic line method can’t come overthe shortcoming of the assumptions that the flow is no-viscosity and no-rotation. Besides, the genetic algorithmand general gradient-based algorithms used for hypersonic nozzles designing can’t handle the challenges ofincreasing number of design variables. Considering the calculation cost of the adjoint method isn’t sensitivewith the number of design variables, this paper uses the discrete adjoint method to design the unilateralexpansion nozzle, accomplishing the parametric model of controlling the area distribution of the nozzle alongthe streamline. On the base of the initial nozzle designed by the genetic algorithm, which already has the greatperformance, the optimization can improve the thrust coefficient with 0.8 percentage points.
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-11-07 Cooperative journals: 《工程热物理学报》
Abstract:激波问题严重影响超/跨音涡轮气动性能、冷却特性和结构完整性,因而,弱化激波设计是高负荷涡轮研究的热点之一。针对这一问题,本文以两个典型超/跨音涡轮叶栅为例,以伴随方法寻优为手段,给定流量和出口气流角约束,在不同工况点下进行优化,并对比研究变工况特性、流动特征和造型参数,探索弱化激波涡轮叶栅设计技术及规律。
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-11-07 Cooperative journals: 《工程热物理学报》
Abstract:目前高超声速喷管的设计方法主要有特征线方法与基于CFD分析的优化设计方法。采用特征线法设计喷管时流动需基于无粘、无旋假设进行简化,无法确保设计结果在真实流动情况下达到最优;采用遗传算法或常规梯度类方法等优化算法进行优化设计时,设计变量数目的增多为设计带来计算量方面极大的挑战。为克服上述方法在设计过程中的不足,依托伴随方法具有计算量与设计变量数目几乎无关的特点,本文发展了基于离散型伴随方法的单边膨胀喷管的设计方法,以控制喷管沿流程的面积分布作为参数化方法,在初步设计的性能优良的原型喷管基础上实现了精细化伴随优化设计,优化后推力系数比原型喷管提升0. 8个百分点。