Convective Heat Transfer Coefficient Equation

Hot surface facing down.

Convective heat transfer coefficient equation. Horizontal plate l 4a p where a is surface area. Q h c a t s t a where. Some typical heat transfer coefficients include. Q heat transferred per unit time w a heat transfer area of the surface m 2 h c convective heat transfer coefficient of the process w m 2 k or w m 2 c t s temperature surface t a temperature air.

The heat transfer coefficient describes the convective heat transfer from a solid to a flowing fluid gas or liquid or vice versa. Free convection air gases and dry vapors. Such a situation can be seen for example with a radiator. Common units used to measure the convective heat transfer coefficient are btu hr ft 2 o f.

Cold air flows past the radiator due free convection and is heated. And p is perimeter. The convective heat transfer coefficient is sometimes referred to as a film coefficient and represents the thermal resistance of a relatively stagnant layer of fluid between a heat transfer surface and the fluid medium. 0 5 1000 w m2k free convection water and liquids.

Horizontal plate l 4a p where a is surface area. Air h 10 to 100 w m 2 k water h 500 to 10 000 w m 2 k. The basic relationship for heat transfer by convection has the same form as that for heat transfer by conduction. H conv 0 59 δt l 0 25.

The rate of heat transfer between a solid surface and a fluid per unit surface area per unit temperature difference. Typical convective heat transfer coefficients for some common fluid flow applications. 10 1000 w m2k forced convection. The convective heat transfer coefficient is dependent upon the physical properties of the fluid and the physical situation.

The formula for heat transfer is. The convective heat transfer coefficient h can be defined as.