Numerical study of amplitude and frequency effects upon a pulsating jet

• Numerical study of the sinusoidal pulsation effects on turbulent plane jet.
• Increase in the Strouhal number generates a fast degeneration of the initial jet region.
• Pulsation amplitude has a very limited effect on the extent of the initial region.
• Pulsation considerably accelerates the jet expansion.
• Pulsation improves the diffusion, the entrainment and the heat exchange.

Sinusoidal pulsation effects on a turbulent plane jet are investigated numerically. In the nozzle exit, the flow is characterized by a uniform temperature, and submitted to a longitudinal and periodic velocity disturbance: u¯(x,y,t)=u¯0+asin(ωt). Upon mixing the spreading and heat exchange with the surrounding medium, properties are influenced obviously by pulsation in the potential core region but they are similar to the steady jet after the end of the potential core.