# Streamwise Normal Stress#

Streamwise normal stress = {yes | no}

## Description / Usage#

The stream-wise normal stress, $$T_{tt}$$, is defined as tt: $$\tau$$, where t is the unit tangent vector to the streamlines computed as v ⁄ $$\mid$$ v $$\mid$$ and $$\tau$$ is the deviatoric part of the dissipative stress tensor,

associated with the Navier-Stokes equations. This variable is called SNS in the output EXODUS II file.

The permissible values for this postprocessing option are

 yes Calculate the stream-wise normal stress. no Do not calculate the stream-wise normal stress.

## Examples#

Following is a sample card:

Streamwise normal stress = yes

## Technical Discussion#

As of 2/9/02 this function is computed with the based viscosity, and not the strain-rate dependent viscosity as might be the case for viscosity models other than NEWTONIAN (see Viscosity card).