DENSITY AND VELOCITY MEASUREMENTS IN TURBULENT HE-AIR BOUNDARY LAYERS
Mots-clés :
Turbulent boundary layer, mixture of gas, flow with variable density, thermo-anemometryRésumé
A turbulent boundary layer with large density variations has been generated by tangential injection of air or helium Into a boundary layer of air-helium mixture. Instrumentation based on thermo- anemometry has been successfully developed for the investigation of this flow Analysis or the mean and fluctuating density fields shows that the flow is mainly governed by the ratio of the injection to the external velocity and that the density ratio plays a secondary role in the mixing processes. However, a sight enhancement of turbulent activity is observed when helium is injected.Téléchargements
Références
- LaRue J.C., Libby P.A., "Measurements in the turbulent boundary layer with slot injection of helium", Phys. Fluids, Vol. 20, n°2, (1977), pp.192-202.
- LaRue J.C., Libby P.A., "Furthers results related to the turbulent boundary layer with slot injection of helium", Phys. Fluids, Vol. 23, n°6, (1980), pp.1111-1118.
- Cheng R.K, Ng T.T., "Some aspect of strongly heated turbulent boundary layer flow", Phys. Fluids, Vol. 25, n°8, (1982), pp.1333-1341.
- Sommer T.P., So R.M.C., Zhang H.S., "Heat Transfer Modeling and the assumption of zero wall temperature fluctuations", J. of Heat Transfer, Vol. 116, (1994), pp.855-863.
- Way J., Libby P.A., "Hot-wire probes for measuring velocity and concentration in helium-air gas mixtures", A.I.A.A.J., 3, n°5, (1970), pp.976-978.
- Purtell L.P., Klebanoff P.S., Buckley F.T., "Turbulent boundary layer at low Reynolds number", Phys. Fluids, Vol.24, n°5, (1981), pp. 802-811.
- Harion J.L., "Influence de différences de densité importantes sur les propriétés de transfert d’une couche limite turbulente", Thèse de doctorat INP Grenoble, (1994).
- Harion J.L., Camano B.E., Favre-Marinet M., "Mesures de vitesse et de concentration par thermo – anémométrie dans des mélanges air – hélium", CRAS Paris, t320 Série IIb, (1995), pp.77-84.
- Riva R., Binder G., Favre-Marinet M., Harion J-L., "Development of turbulent boundary layer with large density gradients", Exp. Thermal and Fluid Science, 9, (1995), pp.165-173.
- Soudani A., "Application des réseaux de neurones aux mesures simultanées en écoulement turbulent", Thèse de doctorat INP Grenoble, (1996).
- Soudani A., "Neural networks: A new method of calibration for the interference probe applied to measurements in air – Helium turbulent boundary layer", Symposium on devices for flow measurement and analysis, USA, (1997).
- Soudani A., Bessaih R., "Application of neural networks to measurements of simultaneous quantities in turbulent flows”, International congress of fluid dynamics and propulsion, Cairo, Egypt, December 29-31 (1996).
- Seban R.A., "Heat transfer and effectiveness for a turbulent boundary layer with tangential fluid injection", J. of Heat Transfer, Vol. 82, (1960), pp.303-312.
- Harmett J.P., Birkebak R.C., Eckert E.R.G, "Velocity distributions, temperature distributions, effectiveness and heat transfer for air injected through a tangential slot into a turbulent boundary layer", J. of Heat Transfer, vol. 83, (1961), pp. 293-306.
- Spalding D.B., "Prediction of adiabatic wall temperature in film-cooling systems”, A.I.A.A.J., 3, n°5 (1965), pp.965-967.
