Fundamentals of Heat and Mass Transfer – Problem 1.15

The free convection heat transfer coefficient on a thin hot vertical plate suspended in still air can be determined from observations of the change in plate temperature with time as it cools. Assuming the plate is isothermal and radiation exchange with its surroundings is negligible, evaluate the convection coefficient at the instant of time when…

To determine the effect of the temperature dependence of the thermal conductivity on the temperature distribution in a solid, consider a material for which this dependence may be represented as k = ko + aT where ko is a positive constant and a is a coefficient that may be positive or negative. Sketch the steady-state…

An electric resistance heater is embedded in a long cylinder of diameter 30mm. When water with a temperature of 25degree C and velocity of 1 m/s flows crosswise over the cylinder, the power per unit length required to maintain the surface at a uniform temperature of 90degreeC is 28kW/m. When air is also at 25…

A blood warmer is to be used during the transfusion of blood to a patient. This device is to heat blood taken from the Blood Bank at 10°C to 37°C at a flow rate of 200 mL/min. The blood passes through tubing of length 2 m, with a rectangular cross-section of 6.4 mm x 1.6…

Heat transfer is a branch of thermal engineering that deals with the production, utilization, transformation, and interchange of thermal energy caused by variations in temperature, leading to changes in temperature distribution. The field of transport phenomena explores the transfer of momentum, energy, and mass through conduction, convection, and radiation. Heat Transfer Background In the early…

You’ve experienced convection cooling if you’ve ever extended your hand out the window of a moving vehicle or into a flowing water stream. With the surface of your hand at a temperature of 30 °C. determine the convection heat flux for a vehicle speed of 35 km/h in air at -5 °C with a convection…