Chapter 7 External Forced Convection7-25Laminar flow of a fluid over a flat plate is considered. The change in the drag force and the rate of heat transfer are to be determined when the free-stream velocity of the fluid is doubled. AnalysisFor the laminar flow of a fluid over a flat plate maintained at a constant temperature the drag force is given by 5.05.02/325.0125.015.021664.02328.1getwelation,number reReynoldsngSubstituti2Re328.1ThereforeRe328.1where2LAALFAFCACFssDsDfsfDυρ∞∞∞∞∞=⎟⎠⎞⎜⎝⎛====VVVVVV∞LWhen the free-stream velocity of the fluid is doubled, the new value of the drag force on the plate becomes 5.05.02/325.02)2(664.02)2()2(328.1LAALFssD∞∞∞=⎟⎠⎞⎜⎝⎛=VVVThe ratio of drag forces corresponding to and 2is V∞V∞FFVVDD22322==∞∞()//23/2We repeat similar calculations for heat transfer rate ratio corresponding to
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 01/22/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.