# Reynolds stress model (RSM)

(Difference between revisions)
 Revision as of 21:44, 16 May 2006 (view source) (→Model constants)← Older edit Revision as of 21:45, 16 May 2006 (view source) (→Introduction)Newer edit → Line 1: Line 1: == Introduction == == Introduction == - The Reynold's stress model (RSM) is a higher level, elaborate turbulence model. It is usually called a ''Second Order Closure''. This modelling approach originates from the work by [[#Referencec|[Launder (1975)]]]. In RSM, the eddy viscosity approach has been discarded and the Reynolds stresses are directl computed. The exact Reynolds stress transport equation accounts for the directional effects of the Reynolds stress fields. + The Reynold's stress model (RSM) is a higher level, elaborate turbulence model. It is usually called a ''Second Order Closure''. This modelling approach originates from the work by [[#Referencec|[Launder (1975)]]]. In RSM, the eddy viscosity approach has been discarded and the Reynolds stresses are directly computed. The exact Reynolds stress transport equation accounts for the directional effects of the Reynolds stress fields. == Equations == == Equations ==

## Introduction

The Reynold's stress model (RSM) is a higher level, elaborate turbulence model. It is usually called a Second Order Closure. This modelling approach originates from the work by [Launder (1975)]. In RSM, the eddy viscosity approach has been discarded and the Reynolds stresses are directly computed. The exact Reynolds stress transport equation accounts for the directional effects of the Reynolds stress fields.

## Equations

The Reynolds stress model involves calculation of the individual Reynolds stresses, $\overline{u'_iu'_j}$ , using differential transport equations. The individual Reynolds stresses are then used to obtain closure of the Reynolds-averaged momentum equation.

The exact transport equations for the transport of the Reynolds stresses, $\overline{u'_iu'_j}$ , may be written as follows:

## Model constants

The constants suggested for use in this model are as follows:

$C_s \approx 0.25, C_l \approx 0.25, C_\gamma \approx 0.25$

## References

Launder, B. E., Reece, G. J. and Rodi, W. (1975), "Progress in the Development of Reynolds Stress Turbulent Closure", Journal of Fluid Mechanics, Vol. 68, pp. 537-566.