A laboratory experiment has been performed to determine the natural-convection heat transfer correlation for a horizontal cylinder of elliptical cross section in air. The cylinder is 1 m long, has a hydraulic diameter of 1 cm, a surface area of 0.0314 m2, and is heated internally by electrical resistance heating. Recorded data include power dissipation, cylinder surface temperature, and ambient air temperature. The power dissipation has been corrected for radiation effects:Ts ?? T?? q(?C) (W)15.2 4.6040.7 15.7675.8 34.2992.1 43.74127.4 65.62Assume that all air properties may be evaluated at 27?C and determine the constants in the correlation equation: Nu = C (Gr Pr)mGIVENA horizontal, elliptical cylinder in airHydraulic diameter (Dh) = 1 cm = 0.01 mLength (L) = 1 mCylinder surface area (As) = 0.0314 m2Experimental data for (Ts ?? T??) and q shown aboveASSUMPTIONSAll air properties may be evaluated at27?C

Transcribed Image Text:

(Grp Pr) x 10 Nup log Nup log (Grp Pr) 3.76 4.81 5.62 0.575 0.682 0.750 0.772 0,806 1.31 1.31 3.51 3.11 3.55 3.81 3.90 4.04 6.53 7.93 5.91 6.40 10.98