Uncovering the physics of thermal signatures in urban street canyons

Started: Oct 2016
Supervisor: van Reeuwijk, M.; Craske, J.

Description of Research

In recent years, research on continuing urbanization have received wide attention. Air pollution and urban heat island are the  most prominent areas of research on urban environment. To meet these environmental challenges, optimal policies are required and, to facilitate such policies, measurements on environmental scales are pivotal.  Field measurements, physical models and numerical simulations are used to measure airflow velocity.  Among these, field measurements and physical models are costly and time consuming. In addition, noisy results obtained from these methods need filtering and thus loose information. Numerical simulations can provide accurate results but at expense of high computational costs.  To minimize the (monetary/computational) cost, flow reconstruction methods from limited observations have been developed. For example, thermal image velocimetry (TIV) requires a low cost infrared camera to capture thermal image on building walls but provides detail information of near wall velocity. The TIV tracks thermal images to calculate velocity at which thermal structures move on a building wall and reconstruct full 2D spatial velocity distribution. However, the TIV can be used only to reconstruct velocity near the wall.

The aim of our project is to reconstruct flow velocity at an arbitrary distance from a building wall using limited thermal wall imprints. We will use structural decomposition techniques, such as POD, to develop appropriate mathematical models and compare them to DNS results.

Background

Rakib is a graduate with a BSc in Mathematics and a MSc in Applied Mathematics from University of Dhaka, Bangladesh. He also carried out a research internship in Faculty of Engineering, Hokkaido University, Japan

RAKIB HOSSAIN
PhD Candidate - Fluid Mechanics 
Department of Civil & Environmental Engineering 
Imperial College London SW7 2AZ 
m.hossain16@imperial.ac.uk