IMECH-IR  > 高温气体动力学国家重点实验室
基于流线追踪的变截面进气道快速设计
Alternative TitleA Quick Design Methodology of Shape Transition Inlets Based on Streamline Tracing
肖鸿文
Thesis Advisor岳连捷
2018-05-25
Degree Grantor中国科学院大学
Place of Conferral北京
Subtype硕士
Degree Discipline流体力学
Keyword变截面进气道 内转式进气道 流线追踪 参考焓法 软件设计
Abstract

高超声速内转式进气道具有压缩效率高、低速条件流量捕获大等优点,是目前高超声速进气道领域研究的热点。基于几何加权和流线追踪技术的变截面内转式进气道设计方法,能够自由设计进出口形状,保持了一定的基准流场性能,同时具有极高的设计效率。设计参数的选取对该类进气道性能的影响较大,而目前对设计参数的相关研究较少。本文发展了基于几何过渡的变截面进气道设计方法,并通过无粘数值计算,考察加权过渡函数、进出口形状参数、加权过渡特征方向对进气道性能的影响,以实现在进气道快速设计方法的基础上对性能进行进一步优化。同时,基于C++和Qt自主研发了内转式进气道快速设计软件,实现了变截面进气道几何构型的实时设计,极大缩短了进气道设计时间,为进气道性能优化和方案论证提供了基础。

按照几何加权的特征方向,发展了两种变截面进气道的设计方法,并基于两种设计方法实现了变截面进气道快速设计,研究了两种加权特征方向下设计的变截面进气道性能和流场。结果表明,流线过渡法有更好的保形特征,而截面加权法会导致进口轮廓线与设计初衷有所不同。数值计算显示,对于本文设计进气道方案,截面加权法设计的进气道具有更高的总压恢复,但其设计压比略低。

论文对5种基本类型过渡函数下设计的进气道性能进行比较,发现反正切函数和幂指数小于1的幂函数有较优的总压恢复性能,这表明在进气道进口附近实现较快的几何过渡有利于进气道总压恢复性能的提升。对这两类过渡函数进一步研究,并得到了相同趋势下具有更佳性能的加权过渡函数。

进一步,对矩形转椭圆形变截面进气道进口的宽高比和出口长短轴比的影响规律进行了研究。随着入口矩形宽高比增加,进气道先升后降。对于出口椭圆形,长短轴比增加时总压恢复先升后降。当矩形宽高比和椭圆长短轴比相同时,进气道性能受所选取比值影响较小,性能相当。

着眼快速设计方法的需求,基于参考焓法提出了对变截面进气道边界层修正的方法,并通过有粘计算验证修正效果。结果表明,修正后的基准流场性能接近无粘结果。对进气道的修正和有粘计算,表明了所发展的内转式进气道快速设计方法合理,设计软件便捷可靠,可获得较高的进气道性能。

Other Abstract

Hypersonic inward turning inlet has advantages of compression efficiency and air capture, which has become hot topic in inlet design field. The shape transition inward turning inlet can be rapidly realized by mathematical weighting method of multiple stream-traced inlet profiles with mathematical functions. This method has extremely high design efficiency while maintaining the key flow characteristics of the baseline flow field. However, the inlet performance is affected by design parameters. The objective of this thesis is to study the effect of design parameters. Meanwhile, a streamline tracing and shape transition inlet design software is programmed based on C++ and Qt. In the graphical user interface, the parameters selection and configuration design of the shape transition inlet are completed, which greatly shortens the design time and provides the basis for the performance optimization and program demonstration of the inlet.

In terms of the characteristic directions of mathematical weighting, two types of methods are studied to achieve the inlet shape transition. The inlet designed by the streamline transition method has better conformal characteristics. The inlet designed by the section transition method has a higher total pressure recovery, but its actual contraction ratio is lower than the design value, and the shape of the capture is changed.

By inviscid numerical calculation, the influence of mathematical weighting function on the performance of the inlet is studied. The results show that among five basic types of transition functions, the arctangent function and the power function whose power exponent is less than 1 have better total pressure recovery performance. The parameters of these two types of functions are further studied, and transition functions with better total pressure recovery are given.

For the rectangular-to-elliptical shape transition inlet, the effect of width-to-height ratio of the captured outline and the ratio of the major-axis to the minor-axis of the outlet are analyzed. The inlet performance decreases sharply when the rectangular aspect ratio increases from 1, and the total pressure recovery increases first and then decreases when the elliptical ratio of the major-axis to the minor-axis increases. The inlet performance is less affected by the selected value when the two ratios are same.

According to the need of design method, the reference enthalpy method is used to modify the inlet boundary layer. The overall performance of modified reference flow field is close to the inviscid result, and the modified variable cross section inlet has good performance.

Call NumberMas2018-026
Language中文
Document Type学位论文
Identifierhttp://dspace.imech.ac.cn/handle/311007/73153
Collection高温气体动力学国家重点实验室
Affiliation中国科学院力学研究所
Recommended Citation
GB/T 7714
肖鸿文. 基于流线追踪的变截面进气道快速设计[D]. 北京. 中国科学院大学,2018.
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