一种抑制超声速气流红外辐射的新途径

A NEW APPROACH FOR SUPPRESSION INFRARED RADLATION OF SUPERSONIC JETS

试验测定了波反馈装置对高温超声速射流的激励效果。主喷管喉道直径为３５ ｍ ｍ ，进口总温和总压分别为８００ Ｋ及２７４．４ ｋＰａ。结果表明，影响激励效果的主要几何参数有锥形反射器的扩张角、反射器母线长度和反射器与主喷管的相对位置。当扩张半角为４５°， 母线长度为４０ｍ ｍ 以及锥形反射器起始截面与主喷管出口齐平时， 激励效果最好， 在Ｘ／Ｄ＝ ６～８ 范围内， 激励后的轴心温度可降低约１２０ Ｋ， 并可望使超声速喷气流的红外辐射强度降低约４０％ ～４５％ 。

Excitation effects for high temperature supersonic jets by acoustic reflector were measured experimentally. The nozzle throat diameter was 35 mm, and the inlet stagnation temperature and pressure were 800 K and 274 4 kPa, respectively. The test results show that the main geometric parameters of the reflector influenting the excitation effects are divergent angle, conic length, the position relatively to nozzle exit. The excitation effects are optimum when the half angle is 45°, the conic length is 40 mm and the initial section of the conic reflector is located at the nozzle exit. The temperature at jet axis is reduced by 120 K as X/D =6～8. Therefore,it is possible that the infrared radiation for high temperature supersonic jets can be reduced by 40%～45%.