Heat Transfer HEAT TRANSFER TERMINOLOGYSummaryThe important information in this chapter is summarized below.Heat Transfer Terminology SummaryHeat is energy transferred as a result of a temperature difference.Temperature is a measure of the amount of molecular energy containedin a substance.Work is a transfer of energy resulting from a force acting through adistance.The Second Law of Thermodynamics implies that heat will not transferfrom a colder to a hotter body without some external source of energy.Conduction involves the transfer of heat by the interactions of atoms ormolecules of a material through which the heat is being transferred.Convection involves the transfer of heat by the mixing and motion ofmacroscopic portions of a fluid.Radiation, or radiant heat transfer, involves the transfer of heat byelectromagnetic radiation that arises due to the temperature of a body.Heat flux is the rate of heat transfer per unit area.Thermal conductivity is a measure of a substance’s ability to transfer heatthrough itself.Log mean temperature difference is the DT that most accurately represents theDT for a heat exchanger.The local heat transfer coefficient represents a measure of the ability to transferheat through a stagnant film layer.The overall heat transfer coefficient is the measure of the ability of a heatexchanger to transfer heat from one fluid to another.The bulk temperature is the temperature of the fluid that best represents themajority of the fluid which is not physically connected to the heat transfer site.Rev. 0 Page 5 HT-02
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business