A 2.5 m high vertical surface is placed exposed to atmospheric and quiescent air. The ambient air temperature is 20°C. A uniform and constant heat flux of 150 W/m2 is imposed on the surface. a....

A 2.5 m high vertical surface is placed exposed to atmospheric and quiescent air. The ambient air temperature is 20°C. A uniform and constant heat flux of 150 W/m2 is imposed on the surface.

a. Calculate the heat transfer coefficient, the boundary layer thickness, and surface temperature at 1 m from the leading edge of the plate.

b. Microscopic particles that are suspended in gas are driven from high-temperature to low-temperature regions. This process is called thermophoresis. In the absence of other particle diffusive transport mechanisms, the slip velocity (velocity between gas and particle) caused by thermophoresis can be found from (Talbot et al., 1980; Friedlander, 2000)

where subscript p represents the particle. The parameter C is the aforementioned Cunningham correction factor and accounts for velocity slip at the particle surface.