Transient heat conduction during quenching of downward facing copper and stainless steel convex surfaces
- Univ. of New Mexico, Albuquerque, NM (United States)
Quenching experiments were performed to determine the effect of wall material properties on pool boiling heat transfer for downward facing convex surfaces (radius of curvature 218.5 mm) in saturated water. Experiments employed 303e-type stainless steel and copper test sections having identical dimensions (75 mm in diameter and 20 mm thick). Pool boiling curves were constructed on the basis of two-dimensional numerical solution of transient heat conduction in spherical coordinates, (r, {theta}) in test sections during quenching. The measured temperature histories at nine interior locations near the boiling surface ({approximately}0.5 mm) provided a time-dependent boundary condition for the numerical solution. To ensure stability and reduce both computer storage and execution time, the numerical solution used the alternating direction implicit (ADI) method with control volume representations. A sensitivity analysis was conducted to assess the effect of grid size on computation time as well as the accuracy of calculated temperatures and pool boiling heat flux values. Best results were obtained using a 20 x 20 network of control volumes and a noniterative approach, whereas the computation time on a Pentium 90-MHz PC for the entire pool boiling curve was about 7% of real time. Calculated temperatures near the top surface ({approximately}5 mm) agreed with measured values to within 0.5 and 2.5 K for copper and stainless steel, respectively. The error in the overall energy balance in the test section, performed after each time interval, was less than 0.001%. The thermal diffusivity of test section material strongly affected both radial conduction within the section and lateral conduction near the boiling surface and, hence, the local pool boiling curves as well as the maximum and minimum pool boiling heat flux values.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 250796
- Journal Information:
- Numerical Heat Transfer. Part A, Applications, Vol. 29, Issue 6; Other Information: PBD: 10 May 1996
- Country of Publication:
- United States
- Language:
- English
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