The present paper can be viewed as an extension of the work of Lim and Sleicher (9). They evaluated the frequency response of the heated element submerged in liquid metal by a perturbation method for Peclet numbers of up to 0.4. Velocity fluctuations were assumed small and second-order perturbations neglected. The Oseen approximation was made to the velocity field. Here the velocity configuration has been approximated to that of potential flow and the convection equation has been solved numerically with the aid of a digital computer. The potential flow approximation, as compared with the Oseen approximation, is reasonable over a larger range of Peclet numbers. Also, our scheme is valid for large amplitudes of fluctuation.
The heat response has been studied under sinusoidal variation in the free stream velocity at frequencies ranging from 1 Hz to 100 kHz for Peclet numbers of up to 1.0. The amplitude of fluctuation was 20% of the mean free-stream velocity. The Nusselt number was found to lag behind the velocity variations and the amount of lag increases with frequency and decreases as the Peclet number is increased. The amplitude of fluctuation of Nusselt number is attenuated as the frequency is increased. The attenuation is 10% at a frequency roughly given by: [formula].
Experimental studies to verify the calculated lag and attenuation effects are in progress.
Malcolm, D. G. and Verma, V., "Dynamic Response of Forced Convective Heat Transfer from Cylinders to Low Prandtl Number Fluids" (1973). Symposia on Turbulence in Liquids. 99.
3rd Biennial Symposium on Turbulence in Liquids (1973: Sep., Rolla, MO)
Chemical and Biochemical Engineering
Article - Conference proceedings
Special Methods of Measurement
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