Hypersonic Thermal Flow Past a Spherically Blunted Tangent-Ogive Nose Cone

極音速球狀切面尖拱形鼻錐之熱流分析

張峰壵(Feng-Yao Chang) ； 翁輝竹(Huei Chu Weng)

《中國機械工程學刊》 43卷1期 (2022/02) Pp. 1-10

摘要

This study conducts a computational fluid dynamics (CFD) simulation to predict the thermal-flow fields and characteristics over a spherically blunted tangent-ogive nose cone at a Mach number of 6. The main objective is to analyze the influence of the bluntness ratio (BR) of the spherically blunted tangent-ogive nose cone on the shock wave, velocity, static pressure, static temperature, and density of the airflow around the nose cone under a fixed base radius, ogive radius, and hypersonic Mach number. The computational results reveal that the BR factor causes a change in shock wave type and shape, an increase in shock detachment distance, and an increase in shock layer thickness, and an enhancement in shock wave strength; furthermore, it makes the airflow static pressure, temperature, and density in the shock layer and on the blunted body surface generally increase, but makes the airflow velocity generally decrease. This study provides useful data for rockets, aircrafts, and reentry vehicles in hypersonic flight, especially the heat distribution of temperature, which involves the material selection and internal temperature control during flying-body design. By adjusting the bluntness ratio, it can be found that the maximum static temperature around the nose cone is 1,812.71 K at BR=0, and reaches 2,453.27 K at BR=1.

關鍵字

gas dynamics ； high-speed flow ； shock waves ； heat transfer ； spherical nose ； tangent-ogive cone ； bluntness ratio ； detachment distance

並列摘要

本研究進行了計算流體動力學（CFD）模擬，以預測馬赫數為6的球狀切面尖拱形鼻錐之熱流場及特性。主要目的是分析在固定的基本半徑、尖拱半徑及極音速馬赫數下，鈍度比（BR）對球狀切面尖拱形鼻錐周圍沖擊波、速度、靜壓力、靜溫度及密度之影響。計算結果顯示，BR因子會引起衝擊波類型和形狀的變化、衝擊脫離距離的增加、衝擊層厚度的增加，以及沖擊波強度的提高。此外，一般而言，BR因子使得衝擊層中和鈍體表面上的氣流靜壓力、靜溫度及密度增加，但使得氣流速度降低。研究結果為極音速飛行中的火箭、飛機及再入飛行器提供了有用的數據，尤其是溫度的熱分佈，這涉及飛行物體設計過程中的材料選擇和內部溫度控制。通過調整鈍度比，本研究可發現鼻錐周圍的最大靜溫度在BR=0時為1,812.71 K，在BR=1時達到2,453.27 K。