基于CFD/CSD耦合方法的旋翼降转速气动特性

A specific tail nozzle of a supercharged ramjet engine was selected as the object of analysis. A three-dimensional finite element analysis method was employed to establish a finite element model of the tail nozzle, enabling investigation of the vibration characteristics of the thin-walled conical shell, structural dynamic response analysis under random vibration conditions, and validation through dynamic experimental tests. The results indicated that the tail nozzle exhibited a diverse range of modal characteristics, primarily characterized by multi-order nodal circle and nodal diameter vibrations. Under axial random vibration loads, the dominant vibration mode observed was m=6, n=1, with the aft section of the nozzle experiencing significant amplitudes and notable amplification of acceleration. This section may be considered as a vulnerable area for dynamic design considerations. The simulation results agreed well with the experimental data, with modal frequency errors within 10%, meeting the requirements for engineering calculations. Therefore, the simulation method with practical value can provide a reference for the dynamic design and evaluation of supercharged ramjet engines.