MED$216$ Heat Transfer

Practice Problems for Test $2$

Problems

$5-29$ Air at $1$ atm and $27C$ blows across a large concrete surface $15$ m wide maintained at $55C.$ The flow velocity is $4\mathrm{.}5\frac{m}{s}.$ Calculate the convection heat loss from the surface.

$8-1$ Fused quartz transmits $90$ percent of the incident thermal radiation between $0\mathrm{.}2$ and $4m.$ Suppose a certain heat source is viewed through a quartz window. What heat flux in watts will be transmitted through the material from blackbody radiation sources at $800C.$

$10-5$ Water at the rate of $68k\frac{g}{m}in$ is heated from $35$ to $75C$ by an oil having a specific heat of $1\mathrm{.}9k\frac{J}{k}gC.$ The fluids are used in a shell$-$and$-$tube exchanger with the water making one shell pass and the oil making two tube passes. The oil enters the exchanger at $110C$ and leaves at $75C.$ The overall heat$-$transfer coefficient is $320\frac{W}{m}2*C.$ Calculate the heat$-$exchanger area.