Numerical Studies on Supersonic Turbulent Flow over a Backward Facing Sharp Edge Step Using Hybrid RANS-LES

Content Provider	Semantic Scholar
Author	Kund, Nirmal Kumar
Copyright Year	2017
Abstract	In the present study, a two dimensional numerical model is developed to investigate supersonic turbulent fluid flow over a backward facing sharp edge step by using both RANS (relating to the standard k-ε model) and hybrid RANS-LES (pertaining to the Spalart-Allmaras model involving viscositylike variable) models. The model also involves additional important factors namely production, diffusion and destruction terms besides the very common aspects related to the present research problem. The numerical simulations are performed using the stated turbulence models with the inflow free stream Mach number of 2.5 along with the free stream pressure and velocity of 15350 N/m and 651.9 m/s, respectively. The simulation predictions are compared with the corresponding experimental results available in the literature. Even though the simulation predictions from both RANS and hybrid RANS-LES models yield satisfactory results, however, the hybrid RANSLES model gives fairly better and consistent results over the RANS model (which provides very good results within the vicinity of the wall region only) throughout the entire flow region and hence, only the hybrid RANS-LES is considered for further investigations. It is also noticed that the sudden viscous layer separation is the prime cause for the generation of reattachment shock. In addition, the uneven pressure recovery is owing to the sudden expansion flow over the sharp edge step. Further, the sudden expansion flow increases the intensity of the shock which leads to uneven flow behaviours. Definitely, the present test case results are very highly beneficial to understand the flow characteristics of supersonic turbulent fluid flow over the backward facing sharp edge step flows. Index Terms – Supersonic, Turbulent Flow, Backward Facing, Sharp Edge Step, RANS, Hybrid RANS-LES
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://www.ijeter.everscience.org/Manuscripts/Volume-5/Issue-11/Vol-5-issue-11-M-24.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article