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R.Sureshkumar February 19, 2000 16:15

Help - Two Phase Flow - Convergence Problem
Hello I am simulating twophase flow (air water spray), in square duct (0.6m x 0.6m x 1.9m length)with counter flow of air and spray. air v = 1 m/s water is sprayed from exit end opposing air flow. I am using FVM - k-e (Launder et al) - SIMPLE - Line by line TDMA for air. Langrangian ODE for droplets (so called discrete models) My simulations for other (required/studied) air velocities (2m/s 3m/s) are over smoothly (some 30 observations, with some playing around with underrelaxation factor for droplet source in air equation).

However! for air velocity 1 m/s, the solution was not converging. I used 65 x 20 grid size. This problem was only while droplet momentum source was added to air eqn./flow. Increasing the grid size did'nt work. Any suggestions insight on this problem.

Louis le Grange February 22, 2000 04:24

Re: Help - Two Phase Flow - Convergence Problem
Dear Mr. Sureshkumar

There may be a few remedies for convergence problems in situations of one-way or two-way coupling. If you are able to download the help file of Flo++ (FloHelp.chm; +- 800KB) from

you will find help on the subject of convergence at the book

Dispersed Multiphase Flows - Convergence behaviour of coupled solutions.

Yours sincerely

Louis le Grange

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