Author: nishan

This page describes some parameters used to measure the properties of boundary layers. Consider a stationary body with a turbulent flow moving around it, like the semi-infinite flat plate with air flowing over the top of the plate. …

• Using APG correction in conjunction with SSM length scale may be redundant.
• SSM Length Scale:  Reduced length scale near-wall region à Reduced eddy viscosity in the outer layer.
• APG correction: Re-calibration of Von Karman constant based on APG

Plane Channel Simulation

• • Channel flow configuration with streamwise and spanwise periodic boundaries
  • Domain size: 8H × 3H × 2H where H is half channel height. Smallest wall-normal spacing is 2 × 10-3 H
  • Grid size sufficient for a well resolved

With respect to STG, the calculation of spatial modes required for synthetic turbulence has been validated and the perturbations are calculated ( v’ in the Shur et al.). Following figures are attached:

Blue portion in figure(b) is the wave numbers …

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Sonic boom minimization – Important challenge

• Intensity depends on the shape and weight of aircraft
• Ex: Quiet Spike Program – updated nose geometry to split the main shock
• Engine nacelles create a sizable boom

More Details …