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Algebraic expressions for the correction factor Fhave been developed for vari- ous shell-and-tube and cross-flow heat exchanger configurations [1–3], and the results may be represented graphically. Selected results are shown in Figures 11S.1 through 11S.4 for common heat exchanger configurations.
Thermodynamics is the study of how heat moves around in ‘macroscopic’ objects. Through-out these lectures, we will talk a lot about laws and models. Models are a simplified, empirical description of a real system which generally develops overtime as our knowledge progresses.
The general function of a heat exchanger is to transfer heat from one fluid to another. The basic component of a heat exchanger can be viewed as a tube with one fluid running through it and another fluid flowing by on the outside.
The natural laws of physics always allow the driving energy in a system to flow until equilibrium is reached. Heat leaves the warmer body or the hottest fluid, as long as there is a temperature difference, and will be transferred to the cold medium. A heat exchanger follows this principle in its endeavour to reach equalisation.
The first law of thermodynamics is a statement of energy conservation as it relates to a thermodynamic system. Heat, which is energy transferred into or out of a system, can be
Heat • The temperature difference determines the direction of heat transfer. • Bodies don’t “contain” heat; heat always refers to energy in transit from one body to another. • We can change the temperature of a body by adding heat to it.
The notes are intended to describe the three types of heat transfer and provide basic tools to enable the readers to estimate the magnitude of heat transfer rates in realistic aerospace applications.
