Experimental and Numerical Analysis of Opaque Turbulent Buoyant Jet

Opaque fluid flow estimation is a challenging problem due to the complex nature of this flow type. Deepwater Horizon oil spill is one of the real examples of opaque fluid flow. Due to the complicated spill flow and the lack of dedicated flow measurement technique its flow rate was estimated with high uncertainty. In this paper, a simulation of jet flow is conducted experimentally and numerically. This is in order to analyze the difference between them. First, a turbulent buoyant jet was experimentally simulated considering various ranges of nozzle flow rates including laminar and turbulent flow. A video camera was used to capture the jet flow. Then, Fast Fourier Transform (FFT) based method was developed to estimate velocity field from video sequence. The outcomes of experimental results were compared to the outcomes of numerical simulation. As a result, the FFT-based method was estimated the nozzle flow rates with a relative error of 18.2% when it was compared to the measured experimental values. Despite this poor accuracy, a good agreement between experimental and numerical simulation outcomes was found in term of overall velocity field, centerline velocity, axial velocity as well as the distribution of radial velocity.