## Special Seminar

**Date: August 7th **

Time: 11:00 AM

Location: Latrobe 106

Speaker: Joe Monaghan

Monash University, Australia

Title: *"*A Turbulence Model For Smoothed Particle
Hydrodynamics*" *

### Abstract

Smoothed particle hydrodynamics is a method for converting continuum equations into particle form. In the case of turbulence we could take continuum turbulence models and convert them to an SPH form. However, a better alternative is to start with the SPH particle equations and use them directly. In this talk I will describe a method for doing this that appears to be simple, elegant, and capable of giving good results, at least for 2D turbulence. The basic idea is related to the LANS-alpha equations but with a different smoothing. We use two velocities. One is the regular velocity obtained from the acceleration equation. The other is a smoothed velocity. A Lagrangian can be constructed using the two velocities, and the Lagrange equations of motion give the Euler equations. To complete the model we add a viscous term. We apply the algorithm to decaying turbulent motion in a box in two dimensions with no slip boundary conditions. We compare our results against those of Clercx and his colleagues who have run experiments and very accurate direct numerical simulations. The agreement is very good. If all goes well I will also discuss the driven turbulence resulting from a real physical stirrer instead of the arcane, stochastic stirring which seems to be the method of choice in the turbulence community.