In fluid dynamics, the entrance length is the distance a flow travels after entering a pipe before the flow becomes fully developed. Entrance length refers to the length of the entry region, the area following the pipe entrance where effects originating from the interior wall of the pipe propagate into the flow as an … See more The hydrodynamic entrance region refers to the area of a pipe where fluid entering a pipe develops a velocity profile due to viscous forces propagating from the interior wall of a pipe. This region is characterized by a non-uniform … See more The thermal entrance length is the distance for incoming flow in a pipe to form a temperature profile with a stable shape. The shape of the fully developed temperature profile … See more Understanding the entrance length is important for the design and analysis of flow systems. The entrance region will have different … See more • Fluid dynamics • Heat transfer • Laminar flow See more The concentration entrance length describes the length needed for the concentration profile in a flow to be fully developed. The … See more Similar to the development of flow at the entrance of the pipe, the flow velocity profile changes before the exit of a pipe. The exit length is much shorter than the entrance length, and is not significant at moderate to high Reynolds numbers. Hydraulic exit … See more WebDec 5, 2011 · Jastrzebski, Z. D.Entrance effects and wall effects in an extrusion rheometer during the flow of concentrated suspensionsInd Eng Chem Fund 6 1967 445 CrossRef Google Scholar. Martin, P. J.Wilson, D. I.A critical assessment of the Jastrzebski interface condition for the capillary flow of pastes, foams and polymersChem Eng Sci 60 2005 493 ...
Fully Developed Internal Turbulent Flows in Ducts and Pipes
WebFor laminar flow, the entrance length can be estimated using the following formula: L_e = 0.05 * Re * D. where L_e is the entrance length, Re is the Reynolds number, and D is the diameter of the pipe. For turbulent flow, the entrance length is typically longer and can be estimated using the formula: L_e = 4.4 * Re^ (1/6) * D. WebDenoted by Le, the entrance length is a function of the Reynolds Number of the flow. In general, ( 7. 1) ( 7. 2) At critical condition, i.e., Red =2300, the Le/d for a laminar flow is 138. Under turbulent conditions it ranges from … north in tucson
Heat Transfer Coefficients (HTC) Correlations
http://www-mdp.eng.cam.ac.uk/web/library/enginfo/aerothermal_dvd_only/aero/fprops/pipeflow/node9.html WebThe density distribution in the entrance region is found to be a function of flow rates of the two phases, of distance from the inlet, and of initial bubble size. Density calculated by the present theory is compared with experimental measurements by the present and other investigators. Theory and experiments are in good agreement. Webthe entrance effect correction. However, certain factors can affect so that the entrance pressure drop values obtained using zero-length capillary become unrealistically high. Probably the most important one is the fact that if the melt extrudate sticks to the walls of the capillary exit region, it causes an extra viscous flow north in the bible means