Technical gazette, Vol. 24 No. 5, 2017.
Original scientific paper
https://doi.org/10.17559/TV-20150707172830
Time-periodic incompressible flow simulation using non-linear frequency domain approach
M. H. Shojaeefard
; Faculty of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran, Iran, 168461
A. Khorampanahi
; Faculty of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran, Iran, 168461
M. Kharati Koopaee
orcid.org/0000-0003-3270-8663
; Faculty of Mechanical Engineering, Shitaz University of Technology, Modares Blv., Shiraz, Iran, 715571
Abstract
The capability of nonlinear reduced frequency domain (NLFD) approach in predicting the flow field of time-periodic incompressible flow is investigated. The efficient NLFD method uses Fourier series representation in time considering the assumption of solution periodicity and the resulting nonlinear equations are solved using pseudo-spectral approach. In this manner, the desired periodic solution can directly be obtained without the need to solve the initial transient part. Thus, without loss of generality a considerable computational cost reduction can be achieved in comparison with the common time-accurate methods. In the present algorithm (INLFD) the NLFD approach is used to solve the flow field in an incompressible formulation and the validation is performed using some periodic test cases with analytical solutions. The results show that capturing only a limited number of temporal modes can provide an accurate estimation of the flow field. Finally, the computational costs of the INLFD and a time-accurate method are also compared which demonstrate the efficiency of the INLFD method in representing nonlinear flow field physics by savings in computational time up to 50 percent.
Keywords
incompressible flow; non-linear reduced frequency; pressure Poisson; pseudo-spectral; time-periodic
Hrčak ID:
188223
URI
Publication date:
25.10.2017.
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