A heat transfer textbook

Improved data correlations have been derived for buoyancy-driven convective heat transfer from the internal surfaces of naturally-ventilated buildings. They cover the full range of laminar, transitional and turbulent airflows, and are based on the mathematical model of Churchill & Usagi (1972). The new correlating equations are presented in a convenient form for incorporating into modern computer programs which simulate the dynamic thermal performance of buildings. They compare favourably with the available exerimental data for isolated surfaces, and are shown to be an improvement on the ‘standard’ correlations recommended in the CIBS Guide. The factors which affect the accuracy of such data correlations, when used for the energy-conscious design of ‘real’ buildings, are briefly discussed.

Improved data correlations for buoyancy-driven convection in rooms:

Natural convective heat transfer coefficient – a review: I. Isolated vertical and horizontal surfaces

Natural convective heat transfer coefficient – a review: II. Surfaces in two- and three-dimensional enclosures

A thermally thick slab of polymethyl methacrylate was used to study the effects of the inclination angle of a fuel surface on upward flame spread. While investigation of upward spread over solid fuels has typically been restricted to an upright orientation, inclination of the fuel surface from the vertical is a common occurrence that has not yet been adequately addressed. By performing experiments on 10 cm wide by 20 cm tall fuel samples it was found that the maximum flame-spread rate, occurring nearly in a vertical configuration, does not correspond to the maximum fuel mass-loss rate, which occurs closer to a horizontal configuration. A detailed study of both flame spread and steady burning at different angles of inclination revealed the influence of buoyancy-induced flows in modifying heat-flux profiles ahead of the flame front, which control flame spread, and in affecting the heat flux to the burning surface of the fuel, which controls fuel mass-loss rates.

M. Al-Arabi

Papers

Natural convection heat transfer from isothermal horizontal plates of different shapes

Natural convection heat transfer from inclined isothermal plates

Heat transfer by natural convection from the inside surface of a uniformly heated tube at different angles of inclination

Heat transfer by natural convection from corrugated plates to air