Abstract: The zero-fuel internal aerodynamic force is significant not only to the scramjet engine thrust performance evaluation but also to the air-breathing hypersonic vehicle aerodynamic performance prediction. A new experimental technique was developed for zero-fuel internal flow force testing. The wind tunnel test at Mach 6 was carried on with a certain circular cross section scramjet engine，and the test results were compared with the internal drag evaluated by the control volume method CV2 based on the theorem of momentum according to the nose-tail force accounting strategy. The results show that the technique for direct-measuring the aerodynamic loads on scramjet engine zero-fuel internal flow by strain-gauge balance is feasible，whose measurement have many advantages，such as high creditability，good reproducibility with the relative error about 4% in the case of inlet staring，high accuracy with the measurement error is within about 3%，abundant information amount，capability of visually and actually reflecting the physical phenomena of internal aerodynamic performance，inlet starting or un-starting and spillage and so on.

Key words: Hypersonic；Wind tunnel test；Scramjet engine；Internal aerodynamic；Strain-gauge balance; Drag

摘要： 不论是超燃冲压发动机推进性能评估，还是吸气式高超声速飞行器气动性能预测，冷态内流气动性能至关重要。为验证冷态内流测力新技术，以采用Nose-to-Tail力核算方法的圆截面超燃冲压发动机为试验对象，在马赫数6条件下开展了风洞试验，并将试验测量结果与基于动量定理的CV2预测方法的内阻评估值进行了对比。结果表明，采用天平直接测量发动机冷态内流气动力载荷的试验方法可行。测量结果可信度高；重复性好，进气道起动时的相对误差约4%；精度高，可控制在3%左右；试验信息丰富，能够直观真实地反映内流气动性能、进气道起动/不起动、溢流等物理现象。

关键词: 高超声速；风洞试验；超燃冲压发动机；内流气动力；应变天平；阻力