Spatially-periodic turbulent forced convection in interrupted-plate rectangular ducts

An experimental study of turbulent forced convection from the plates in the spatially-periodic fully-developed region of air flows in a straight rectangular duct fitted with interrupted-plate inserts is presented. These flows have features akin to those produced in the cores of offset-fin compact heat exchangers. A technique based on the lumped parameter analysis was proposed to determine average heat transfer coefficients on the surfaces of specially designed and instrumented test plates installed in the spatially-periodic fully-developed flow region. This technique was validated using complementary numerical simulations of unsteady three-dimensional heat conduction inside the plates. The results were obtained for Reynolds number (based on the average velocity in the minimum cross-sectional area and a hydraulic diameter) in the range 2,000 to 30,000. The main goal of this experimental research was to obtain reliable heat transfer results that could be used to check and refine corresponding mathematical models and numerical solution methods