Chemical Engineering & Technology, Vol.33, No.9, 1506-1514, 2010
Effects of Flow Pulsation on Forced Convection in a Channel Containing Regularly Spaced Nonconducting Fins
The effects of pulsating flow on forced convection in a rectangular channel containing a series of regularly spaced, nonconducting inserts were investigated experimentally. Based on the experimental data, a correlation equation was developed. The steady-flow Reynolds number Re in the laminar range, Re < 1200, was examined. The Prandtl number of the working fluid Pr = 15 and the oscillation was generated using low-frequency oscillation at f < 50 Hz and amplitude A < 1 mm. The energy dissipation as a result of applied oscillation was determined by phase-resolved measurements of pressure difference and liquid displacement. The system shows improved convective heat transfer towards a low Reynolds number. At a higher Reynolds number, the influence of the oscillation diminished and the flow approaches a steady finned flow. The predictions of the developed correlation equation are in good agreement with the experimental data. The calculated power input due to oscillation is comparatively low and decreases towards increasing net flow rates where the oscillating flow has a diminishing effect.