The paper records new data on the local heat transfer coefficient in a straight pipe remote from the entrance. Water and air were used, at Reynolds numbers from 300–100,000; the pipes were horizontal, of seven different diameters from 1.27 to 5.08 cm. Temperature differences were small. ...
Pipe diameter (mm) \({\text{f}}\) : Friction factor h: Convectional heat transfer coefficient (W m − 2K−1) k: Thermal conductivity (W mK−1) L: Length of the test section (mm) \(\dot{m}\) : Flow rate (kg s−1) Nu: Nusselt number P: Pressure (Pa...
Heat Transfer Coefficient, U Theheat transfer coefficient, U, is dependent on the following variables: 1. Thermal conductivityof metal, medium, and product. 2. Thickness of metal in pipe wall. 3. Fluid velocity. 4. Specific heat. 5. ...
The numerical results revealed that mean heat transfer coefficient for latent microcapsule slurry was about 1.3〜1.8 times greater than that for the single phase of water. 展开 关键词: Solid-Liquid Phase Change Melting Heat Transfer Latent Microcapsule-Water Slurry Constant Wall Heat Flux Numerical...
The heat transfer data with slug air-water flow pattern were measured under a uniform wall heat flux boundary condition. The change on the heat transfer with inclination angle compared to the horizontal case is discussed in terms of the change in the overall heat transfer coefficient with respect...
The overall heat transfer coefficient for a multi-layered wall, pipe or heat exchanger - with fluid flow on each side of the wall - can be calculated as 1 / U A = 1 / hciAi+ Σ (sn/ knAn) + 1 / hcoAo(2) where U = the overall heat transfer coefficient (W/(m2K), Btu/(ft2...
The numerical modeling of the conjugate heat transfer and fluid flow of Al2O3/water nanofluid through the micro-tube was presented in the paper. The laminar flow regime was considered along with viscous dissipation effect. The diameter ratio of the micro-tube was Di/Do = 0.1/0....
Reynolds(Re),andPrandtl(Pr)numbersrespectively.TheNusseltnumberforheattransferfromafluidtoapipeorfromapipetoafluidequalsthefilmcoefficientmultipliedbyd/k Nuhdk Thefilmcoefficienthistheaveragevalueoverthelengthofthepipe PrandtlnumberPristheratioofthediffusivityofmomentumμ/ρtothethermaldiffusivityk/ρcp Prcp k ...
Condensation coefficient of water Chem. Engng Sci. (1963) B.V. Deryagin et al. Effect of film transfer upon evaporation of liquids from capillaries Bull. R.I.L.E.M. (1965) P.C. Wayner et al. Heat and mass transfer in the vicinity of the triple interline of a meniscus A.I.Ch.E...
Heat transfer enhancement was investigated in a coaxial-pipe heat exchanger using dimples as the heat transfer modification on the inner tube. Tube-side Reynolds numbers were in the range of 7.5×103–5.2×104 for water flow. A constant annular mass flow rate was chosen to obtain the highest ...