Flow optimization and aerodynamic noise reduction of high-speed maglev trains based on air blowing/sucking
摘要
The increasing aerodynamic noise caused by high-speed maglev trains (HSMTs) contributes substantially to environmental pollution and passenger discomfort. Numerical studies were performed to examine the effect of air blowing/sucking modes, positions and velocities on the flow field change and their potentials in mitigating the aerodynamic noise produced by HSMTs. The results indicate that the aerodynamic noise can be effectively mitigated by implementing air-blowing in the transition region between the streamlined tail nose and constant cross-sectional body (Scheme 1) and the wake vortex shedding area near the tail nose (Scheme 3) at speeds below 0.3U (train speed), as well as in the side edge area (Scheme 2) at various speeds (0.1U–0.5U), primarily due to the suppression in wake vortices. The optimal noise reduction value of 1.53 dB(A) is achieved when blowing in Scheme 1 at a speed of 0.1U, while the efficacy of the air-sucking mode is inferior with a smaller noise reduction value less than 0.84 dB(A). Additionally, simultaneous reductions in aerodynamic noise and drag can be achieved when sucking in Scheme 2 at speeds below 0.2U and blowing in Scheme 3 at speeds below 0.3U. These findings offer valuable insights for the application of active flow control technology in the design of low-resistance and low-noise HSMTs.