Experimental Research about Shock Wave in a 1+1/2 Counter-Rotating Turbine

Chao Li,Huo-Xing Liu,Zhi-Hong Zhou

doi:10.1051/matecconf/201815102005

Abstract

To investigate the internal distribution regularities of shock wave structure in 1+1/2 counter-rotating turbine, numerical simulation and experimental research about the shock wave structure were conducted by using the schlieren apparatus under different working conditions.From the point of the unsteady results, the unsteady effect has few influence on the flow field of high pressure guide vane, but the wake of the high pressure guide leaves periodically sweeps through the front edge of the high pressure blade and there presents strong unsteady effect on flow field of high pressure rotor. Because of periodic influence of external wake and shock wave, the unsteadiness of flow in low pressure rotor is still strong but not that drastic compared to the high pressure rotor. 50% height section of the blade of the three types of blades are extracted respectively to make plane cascades which are conducted blowing experiments in supersonic wind tunnel. The final photograph were analyzed by comparing with the CFD results. Results show that with the increase of expansion ratio, the wave structures in blade channel move toward the exit and the caudal interference between the outer tail wave and is strengthened gradually.

Highlights

In 1+1/2 counter-rotating turbine, the high-pressure turbine has one stage, which contains a complete guide vane and a rotor blade
To investigate the internal distribution regularities of shock wave structure in 1+1/2 counter-rotating turbine, numerical simulation and experimental research about the shock wave structure were conducted by using the schlieren apparatus under different working conditions.From the point of the unsteady results, the unsteady effect has few influence on the flow field of high pressure guide vane, but the wake of the high pressure guide leaves periodically sweeps through the front edge of the high pressure blade and there presents strong unsteady effect on flow field of high pressure rotor
In 1993, Huber from NASA's lewis research center studied counter-rotating turbine in a liquid rocket engine [6] and the results showed that the efficiency of turbine without a second-level turbine guide vane increased by 2%

Summary

Introduction

In 1+1/2 counter-rotating turbine, the high-pressure turbine has one stage, which contains a complete guide vane and a rotor blade. The conter rotation of HP and LP turbine can greatly reduce or eliminate the gyroscopic moment in the engine [2]and improve the maneuverability and operability of the aircraft [3]. It can reduce the weight of the turbine from the aspect of structure, which makes the engine structure more compact [4]. In 1993, Huber from NASA's lewis research center studied counter-rotating turbine in a liquid rocket engine [6] and the results showed that the efficiency of turbine without a second-level turbine guide vane increased by 2%. Numerical simulation were carried out for a 1+1/2 contra-rotating turbine under design conditions to obtain distribution regulations of the shock wave structure in blade fields, and schlieren technique was introduced to get the detailed shock wave structure, followed by analyzation of the experimental results

Computational Grid

The Calculation Results

The experimental study

Experimental Equipment

Experimental Results

Conclusion