Physical simulation of dry microburst using impinging jet model with swirl

Abstract

Severe thunderstorm is an important weather phenomena, which impact on aviation, space vehicle launching, agriculture in
addition to its damage potential to life and properties. One of the most important event in the thunderstorms is the “Downburst”. It consists of slow rotating column of air, which burst violently after reaching the ground. It is believed that a downburst is generated when the upward moving moist buoyant air can no longer be sustained above and subsided into downdraft. The flow due to downburst impacts on the ground and spreads outward in different directions. Downbursts are classified as either microburst or macroburst depending on their horizontal extent of damage. In this work, an attempt has been made to simulate the dry microburst (microburst not accompanied by rain) experimentally using the impinging jet model for investigating the macroflow dynamics and scale (Reynolds number) dependency of the downburst flow. Flow visualization is done using a smoke generator for understanding the flow dynamics.