Heat Transfer quiz 2 Ramirez

A concrete wall consist of 450 mm red clay brick with thermal conductivity of 1 (SI units). It is lined on the inner face with 15 mm gypsum plaster with thermal conductivity of 0.4 (SI units). If the inside wall surface is maintained at 25 deg C and the outside wall surface temperature of the brick is 37 deg. C. Determine the heat flow per unit area.

Estimate the temperature in the previous number between the brick and the gypsum in deg C.

Water is cooled in a double pipe counter current heat exchanger from 120 deg C to 100 deg C with air entering at 60 deg C and leaving at 75 deg. C. The LMTD for the heat exchanger is 

You are asked to design cylindrical steel rod if 50.0 cm long with a circular cross section, that will conduct 150 W from a furnace at 400 deg C to a container of boiling water under 1 atm. What must the rod's diameter be?

What is the Absorptivity of concrete at 3333.6 K?

A pot with a steel bottom 8.5 mm thick rests on a hot stove. The are of the bottom of the pot is 150 m2 . The water inside the pot is at 100 deg C and 0.39 kg are evaporated every 3 minutes. Find the temperature of the lower surface of the pot, which is in contact with the stove.

The hot glowing surfaces of the starts emit energy in the form of electromagnetic radiation. It is a good approximation to assume emissivity = 1 for these surfaces. Find the Radii of rigel, the brigh blue start in the constellation orion which radiates energy at a rate of 2.7 x 1023 W and has a surface temperature of 11000 K.

Among liquids, water has a comparatively high value of thermal conductivity, due to its

The sum of reflectivity and absorptivity for an opaque body is equal to

The ratio of kinematic viscosity to thermal diffusivity is called the __________ number.