高超声速尖锥边界层压力脉动和热流脉动特性试验

Experimental research on characteristics of pressure and heat flux fluctuation in hypersonic cone boundary layer

高频脉动热流是激波风洞研究高超声速边界层转捩的重要测试量,利用尖锥模型在中国空气动力研究与发展中心Ф2 m激波风洞(FD-14A)内开展来流马赫数10、单位雷诺数分别为1.2×10^(7)/m、4.7×10^(6)/m、2.4×10^(6)/m流场条件下的风洞试验。获得了不同工况和流态条件下尖锥模型边界层热流脉动和压力脉动频谱特性,通过与高频脉动压力频谱结果和线性稳定性理论计算结果对比,证明了自研的原子层热电堆热流传感器(ALTP)的频谱响应能力,可用于高超声速边界层转捩研究工作。试验发现热流脉动具有压力脉动不一样的频谱特征,湍流条件下压力脉动的各频率能量分布比较均匀,而热流脉动随频率增大能量衰减比较明显;相比于压力脉动,热流脉动信号更不容易受到干扰,本次试验在马赫数10、单位雷诺数2.4×10^(6)/m流场条件下,测量的热流脉动第二模态波峰值频谱相对于压力脉动更早凸显出来。

High-frequency heat flux fluctuation is important in shock tunnel tests for experimental investigation of hypersonic boundary layer transition.A cone model is applied to test the self-innovated Atomic Layer Thermopile(ALTP)heat-flux sensors under the experimental condition of Mach number 10 with the unit Reynolds number being 1.2×10^(7)/m,4.7×10^(6)/m and 2.4×10^(6)/m,respectively,in theФ2 m shock tunnel(FD-14 A)of China Aerodynamics Research and Development Center.The tests obtained the spectrum characteristics of the heat flux and pressure fluctuation in the cone model boundary layer under different flow conditions,and through comparison with the high-frequency pressure fluctuation and N factor from linear stability theory computation,the spectrum response capability of the self-innovated ALTP heat-flux sensor is confirmed,indicating its applicability to the research on hypersonic boundary layer transition.The test results show that the heat flux fluctuation has a different spectrum characteristic from that of the pressure fluctuation;the pressure fluctuation energy distribution is relatively uniform under turbulent conditions,while the heat flux fluctuation energy decays more obviously with frequency increase;compared to the pressure fluctuation,the heat flux fluctuation signal is less susceptible to interference;the peak spectrum of the second mode wave of the heat flux fluctuation became prominent earlier than that of the pressure fluctuation in the flow field of Mach number 10 with the unit Reynolds number 2.4×^(6)/m.