Simulation of High-Temperature Effects and Nozzle Afterbody Flows with Unstructured Grids

高溫效應及噴嘴／後體流場於非結構性網格之數值模擬

劉登(Dun C. Liu)

《中國航空太空學會學刊》 28卷4期 (1996/12) Pp. 287-296

https://doi.org/10.6124/TAASRC.199612_28(4).03

摘要

本文討論極超音速流動現象於非結構網格之數值模擬。計算方法爲適量向量分離法及通量差異分離法。文中採用等效比熱率作法以反應真實氣體效應。分析案例討論進氣道及軸對稱擴張管內流場高溫效應。男一方面，亦分析極超音速飛行時噴嘴／後體附近高速低溫流場以顯示氣動力與推進整合設計特性。文中並建議修正後體斜坡形狀之簡化程序以利提昇推力。該程序緣於一維等熵條件。測試案例成功顯示其成效。

並列摘要

Present study is focused on numerical simulation of hypersonic flows with unstructured grids. Euler equations are solved by using upwind schemes, including flux-vector splitting and flux-difference splitting. Real gas effects are captured by employing an ”equivalent” γ representation. The high-temperature internal flow through an inlet and that through an axisymmetric diffuser are solved to illustrate the high-temperature effects. On the other hand, the specific low- temperature hypersonic flow around a nozzle-afterbody flow is studied to demonstrate the nature of airframe-propulsion integration. A simple correction procedure is suggested to modify the shape of ramp surface with the aim of improving the thrust force. This procedure resembles the one-dimensional isentropic constraint. Its effectiveness is illustrated with an example.

並列關鍵字

hypersonic flow ； unstructured grids ； upwind schemes