Search results
Results From The WOW.Com Content Network
Bulk temperature. In thermofluids dynamics, the bulk temperature, or the average bulk temperature in the thermal fluid, is a convenient reference point for evaluating properties related to convective heat transfer, particularly in applications related to flow in pipes and ducts. The concept of the bulk temperature is that adiabatic mixing of ...
Convection (or convective heat transfer) is the transfer of heat from one place to another due to the movement of fluid. Although often discussed as a distinct method of heat transfer, convective heat transfer involves the combined processes of conduction (heat diffusion) and advection (heat transfer by bulk fluid flow).
The general definition of the heat transfer coefficient is: where: : heat flux (W/m²); i.e., thermal power per unit area, : difference in temperature between the solid surface and surrounding fluid area (K) The heat transfer coefficient is the reciprocal of thermal insulance. This is used for building materials (R-value) and for clothing ...
When considering the flow of fluid is a result of heating, the following correlations can be used, assuming the fluid is an ideal diatomic, has adjacent to a vertical plate at constant temperature and the flow of the fluid is completely laminar. [52] Nu m = 0.478(Gr 0.25) [52] Mean Nusselt number = Nu m = h m L/k [52] where
v. t. e. The first law of thermodynamics is a formulation of the law of conservation of energy in the context of thermodynamic processes. The law distinguishes two principal forms of energy transfer, heat and thermodynamic work, that modify a thermodynamic system containing a constant amount of matter. The law also defines the internal energy ...
An example of steady state conduction is the heat flow through walls of a warm house on a cold day—inside the house is maintained at a high temperature and, outside, the temperature stays low, so the transfer of heat per unit time stays near a constant rate determined by the insulation in the wall and the spatial distribution of temperature ...
Water has a surface tension of around 0.07 N/m, and a viscosity of approximately 10 −3 Pa s, at room temperature. So even variations of a few percent in the surface tension of water can generate Marangoni flows of almost 1 m/s. Thus Marangoni flows are common and easily observed.
A clepsydra is a clock that measures time by the flow of water. It consists of a pot with a small hole at the bottom through which the water can escape. The amount of escaping water gives the measure of time. As given by the Torricelli's law, the rate of efflux through the hole depends on the height of the water; and as the water level ...