Zero-fuel internal flow force test for circular cross section scramjet engine

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.