Direct numerical simulation of self-similar turbulent boundary layers in adverse pressure gradients

Citation
M. Skote et al., Direct numerical simulation of self-similar turbulent boundary layers in adverse pressure gradients, FLOW TURB C, 60(1), 1998, pp. 47-85
Citations number
32
Categorie Soggetti
Mechanical Engineering
Journal title
FLOW TURBULENCE AND COMBUSTION
ISSN journal
13866184 → ACNP
Volume
60
Issue
1
Year of publication
1998
Pages
47 - 85
Database
ISI
SICI code
1386-6184(1998)60:1<47:DNSOST>2.0.ZU;2-X
Abstract
Direct numerical simulations of the Navier-Stokes equations have been carri ed out with the objective of studying turbulent boundary layers in adverse pressure gradients. The boundary layer flows concerned are of the equilibri um type which makes the analysis simpler and the results can be compared wi th earlier experiments and simulations. This type of turbulent boundary lay ers also permits an analysis of the equation of motion to predict separatio n. The linear analysis based on the assumption of asymptotically high Reyno lds number gives results that are not applicable to finite Reynolds number flows. A different non-linear approach is presented to obtain a useful rela tion between the freestream variation and other mean flow parameters. Compa rison of turbulent statistics from the zero pressure gradient case and two adverse pressure gradient cases shows the development of an outer peak in t he turbulent energy in agreement with experiment. The turbulent flows have also been investigated using a differential Reynolds stress model. Profiles for velocity and turbulence quantities obtained from the direct numerical simulations were used as initial data. The initial transients in the model predictions vanished rapidly. The model predictions are compared with the d irect simulations and low Reynolds number effects are investigated.