TAILIEUCHUNG - Heat Transfer Handbook part 67

Heat Transfer Handbook part 67. The Heat Transfer Handbook provides succinct hard data, formulas, and specifications for the critical aspects of heat transfer, offering a reliable, hands-on resource for solving day-to-day issues across a variety of applications. | 654 BOILING XT anb a Nu ------------ kl _g pL - Pg using the bubble departure diameter which is the bracketed term in eq. as the characteristic length and anb is the nucleate pool boiling heat transfer coefficient. He defined the Reynolds number using hie siiperflcial velocity of the liquid as r qt 2 Re -------------a Pl hLGpL Lg pL - pG RL where P17 is the liquid Prandt number. For the lead constant C1 he introduced the empirical constant Csf to account for hie particular liquid-surlaco cbmbination so that Nu Re1-n Pr-m Csf which he presented in the form CpL AT hLG Csf q - - a 1 2 Rl lg .g fiL - Pg . n Pr m 1 Thus this gives AT a qn and anb is obtainable from its definition . anb q M where AT Tw Tsai and Tw is the wall temperature . The exponents are m and n thus equivalent to q a AT3 except for water where m 0. Physical properties are evaluated at the saturation temperature of the fluid. Rohsenow provided a list of values of Csf for various surface-fluid combinations that has been extended by Vachon et al. 1967 in Table . Because this method requires a surface-fluid factor it is inconvenient to use for general thermal design. TABLE Values of Csf for Rohsenow Correlation Liquid-Surface Combination Csf n-Pentane on polished copper n-Pentane on polished nickel Water 111 pohshed copper Carbon tetrachloride on polished copper Wateron lapped copper n-Pentane on lapped copper n-Pentane on emery polished copper Wateron scored copper Water on grondd add polished t lin n less sIicI Water od PTFE pttted sbrantess sleel Wateron chemically etched stainless steel Wateron mechanically polished stainless steel POOL BOILING HEAT TRANSFER 655 Reduced Pressure Correlation of Mostinski Mostinski 1963 applied the principle of corresponding states to the correlation of nucleate pool boiling data arriving at a reduced pressure formulation without a .

• Điện - Điện tử
• Cẩm nang truyền nhiệt
• nghiên cứu ứng dụng
• truyền nhiệt trong các thiết bị điện tử
• khái niệm truyền nhiệt và ứng dụng
• nhiệt động NIST