Heat pipes liquid pressure distribution

Figure 13.2 shows the distribution of different operating parameters in a heat pipe. Figure 13.2(a) shows the wick structure and the interface of the liquid-vapor film. Figure 13.2(b) shows the wall temperature of the heat pipe and the corresponding vapor temperature distribution. Figure 13.2(c) shows the vapor and liquid pressure distribution. The liquid pressure drop from the condenser side to the evaporator side is due to Darcy pressure drop. Figure 13.2(d) indicates that the liquid and vapor flow rates are equal at any cross section as there is no inflow and outflow due to the closed end of the heat pipe. 

FIGURE 12.3 (a) variation of meniscus curvature as a function of axial position [7] (b) typical liquid and vapor pressure distributions in a heat pipe [7],... 

Economic Pipe Diameter, Laminar Flow Pipehnes for the transport of high-viscosity liquids are seldom designed purely on the basis of economics. More often, the size is dictated oy operability considerations such as available pressure drop, shear rate, or residence time distribution. Peters and Timmerhaus (ibid.. Chap. 10) provide an economic pipe diameter chart for laminar flow. For non-Newtouiau fluids, see SkeUand Non-Newtonian Flow and Heat Transfer, Chap. 7, Wiley, New York, 1967). 

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