报告题目：Sound generation from movingboundaries

主讲人：孙晓峰/杜林

报告时间：2017年11月30日(周四)12:10

报告地点：新主楼第1报告厅

报告内容简介：

A high-ordercomputational model is developed to simulate the flow-induced sound problemswith arbitrarily moving boundaries, on the basis of a discretized forcingimmersed boundary method. The “2H2U” optimal criteria are proposed toillustrate the importance of a suitable body force model for developinghigh-order methods to simulate this kind of problems without bringing parasitewaves near wall boundaries. A model equation is introduced to analyze theconvergence and stability qualities of the present immersed boundary method,thus to obtain the optimal grid size ratio. To demonstrate the capability ofthe computational model and the reasonability of the proposed “2H2U” criteria,three kinds of flow-induced sound benchmark problems are simulated by utilizingthe developed in-house compressible solver. Excellent agreements are obtainedwith the previous results both for the near-field flow structures and soundfields for the first kind of benchmark problem. In particular, it is provedthat the developed computational model allows a larger CFL number than thepenalization method and ghost-cell method for the flow-induced sound problems.

主讲人简介：

Lin Du is associatedProfessor of Fluid and Acoustic Engineering Laboratory, School of Energy andPower Engineering, Beihang University. Dr. Du’s research interests include therotor/stator interaction, fluid-structure interaction and aeroacoustics inturbomachinery. A computational platform is established to solve the unsteadyflow associated with moving boundary problems on the basis of immersed boundarymethod. The numerical method is developed to simulate laminar/turbulent flow,incompressible/compressible flow. The code is parallelized to reduce thecomputational time. In the frame of the present method, the unsteady flowpassing through blade rows in turbomachinery can be studied on fixed simpleorthogonal meshes. The data transfer at the interface between moving andstationary grids which slip against each other in traditional numerical methodsis avoided. This is significant to elaborate the effect of rotor/statorinteraction by numerical simulations. This method is also applied to studyfluid-structure interaction and sound generation of complex moving boundaries.