Free and Impinging Jet Flow

The goal of this study is to understand the effect of latent heat release on entrainment in cumulus clouds by employing a laboratory analogue consisting of a volumetrically heated turbulent axisymmetric jet. The jet fluid is volumetrically heated in an off-source manner to simulate condensation heat release in clouds. The application of wholefield velocimetry and thermometry allowed us to probe the velocity and temperature fields within the heat injection zone in great detail (see figure). This work led to the development of a simple model to explain reduced entrainment in cumulus clouds.

Effect of off-axis volumetric heating on a turbulent jet. (The flow is from bottom to top.)(left), ) Laser induced florescence (LIF) image(right)

We have also conducted detailed experiments for impinging jet flow. Such flows are of interest because they give among the highest value of single-phase heat transfer coefficient, and are therefore extensively employed in industrial settings.

References

  1. Yadav, H., Agrawal, A., Srivastava, A., "Mixing and Entrainment in a Pulse Jet," International Journal of Heat and Fluid Flow (to appear).

  2. Yadav, H., Srivastava, A., Agrawal, A., "Characterization of pulsating submerged jet – A PIV study," ASME Journal of Thermal Science and Engineering Applications, Vol. 8, 011014 (9 pp), 2016.

  3. Hashiehbaf, A., Baramade, A., Agrawal, A., Romano, G.P. "Experimental Investigation on an Axisymmetric Turbulent Jet Impinging on a Concave Surface," International Journal of Heat and Fluid Flow, Vol. 53, pp. 167-182, 2015.

  4. Agrawal, A., "A conceptual model of entrainment in cumulus clouds," Journal of Atmospheric Sciences, Vol. 62, No. 7, pp 2602-2606, 2005.

  5. Agrawal, A., Boersma, B.J., and Prasad, A.K., "Direct numerical simulation of an axisymmetric turbulent jet with off-source buoyancy induced acceleration," Flow, Turbulence and Combustion, Vol. 73, No. 3/4, pp. 277-305, 2005.

  6. Agrawal, A., and Prasad, A.K., "Evolution of a turbulent jet subjected to volumetric heating," Journal of Fluid Mechanics, Vol. 511, pp. 95-123, 2004.

  7. Agrawal, A., Sreenivas, K.R., and Prasad, A.K., "Velocity and temperature measurements in an axisymmetric turbulent jet with cloud-like off-source heating," International Journal of Heat and Mass Transfer, Vol. 47, No. 6/7, pp. 1433-1444, 2004.