Explore BrainMass


Convection is the transfer of heat from one region to another through the motion of fluids. Convection is the most common form of heat transfer. Convection can happen in one of two ways.

The first way of convection is forced convection. This occurs when a fluid is forced to flow over the surface by an external source. The motion which is created is an artificially induced convection current. An example of this type of convection is when a fan is blowing on a hot surface to cool it down faster. 

The second way of convection is free convection, also referred to as natural convection. This is when the fluid movement is caused by the variations of temperature in the fluid. For example, when the fluid touches a warm surface, the molecules scatter which causes the fluid to be less dense. The colder fluid gets more dense and will sink. Therefore the more hot volume transfer heat towards the cooler volume of that fluid.

There is a device which works as heat of pump

There is a device which works as heat of pump. This device is able to heat the air at 1 degree per second. The velocity of hot air is 0.5 m/sec. The professor is placing an alluminium cup full of water. The problem is, how long its going to take the hot air from heating pump to rise the water from 25 deg to 34 deg. You are

Forced Convection Temperatures

The temperature of a gas stream is measured by a thermocouple whose junction can be approximated as a 1.2mm diameter sphere. The properties of the junction are: K = 40.5 W/m*k p= 7950 kg/m^3 Cp= 345 J/kg*k The heat transfer coefficient between the junction and the air where h= 250 W/m^2 * K Determine how long

Airplane - Heat Problem

Please view attached heat problem. I am having trouble understanding the cylinder part/ and should be used to find the temperature. any help would be appreciated. thanks Assume that the body of an airplane is considered as a 20-m long hollow cylindrical structure made up of unknown composite material. The plane body has insi

Thermal Conductivity in an Oven Wall

The composite wall of an oven consists of three materials, two of which are of known thermal conductivity, kA = 20 W/m?K and kC = 50 W/m?K, and known thickness, LA = 0.30 m and LC = 0.15 m. The third material, B, which is sandwiched between materials A and C, is of known thickness, LB = 0.15m but the thermal conductivity kB is

Sunk Costs, Relevant Cost

Please see attachment. 6. Pat, a Pizzeria manager, replaced the convection oven just six months ago. Today, Turbo Ovens Manufacturing announced the availability of a new convection oven that cooks more quickly with lower operating expenses. Pat is considering the purchase of this faster, lower operating cost, convection ove

Unit Length Heat Loss and Describing a Thermal Circuit

Please see the attached file for the fully formatted problem(s). Find unit length heat lost and describe the thermal circuit. Copper pipe inside radius r1 = 1cm And thickness of pipe = 0.3 cm So pipe outside radius r2 =1.3cm Thickness of insulated material = 1cm Radius of pipe with insulation r3 =2.3cm Thermal conduct

Natural Convection

Please see the attached file for the completely formatted problem(s). A hot plate with an insulated back is considered. The rate of heat loss by natural convection is to be determined.

Heat Transfer: a Plane Wall; Find Maximum Temperature in Wall

A plane wall of thickness 0.1 m and thermal conductivity of 25 W/mL. The volumetric heat generation of the wall = 0.3 MW/m^3. The wall is well insulated on one side while the other side is exposed to a fluid at 92 degrees Celsius with a convection heat transfer coefficient of h=500 W/m^2. What is the maximum temperature in the w