Seminar Series

Heat Transfer and Entropy Production Evaluation on Premixed Hydrogen/Air-fuelled Micro-combustors with Internal Threads

Speaker

Ph.D. Student Siliang Ni

Institute

Department of Mechanical Engineering, University of Canterbury

Time & Place

Mon, 12 Jul 2021 11:20:00 NZST in E12, Engineering Core

All are welcome

Abstract

A micro-combustor with a tailored internal thread is proposed to uniform the wall temperature and improve the second law efficiency of micro thermophotovoltaic (MTPV) system. The influences of 1) the thread form, 2) inlet velocity and 3) nominal diameter on the thermal performance are investigated by performing computational fluid dynamics simulations. Results indicate that the application of corrugated thread structures can reduce the flame temperature and enhance heat transfer remarkably. The recirculation zone formed in the spiral grooves is conducive to obtaining uniform temperature on the outer surface. Especially when the inlet velocity increases to 5 m/s, the standard deviation of wall temperature can be maintained below 20 K. In addition, the mean wall temperature and standard deviation of wall temperature both increase distinctively with the increase of nominal diameter. Entropy production is analysed for combustors with different thread forms. Moreover, the second law efficiency of the triangular thread is above 65% while the entropy production from chemical reaction and heat conduction contribute more than 80%. The present work provides a new design of the internal structure for the optimization of the micro-combustors.

Seminar-Siliang Ni

Supervisor: Prof Dan Zhao