This paper presents a numerical model for the conical entrance orifice plate flow sensor, which is essentially used as a low Reynolds number flow measuring device. The model was developed using a low Reynolds number k-ɛ model of turbulence – the Lam and Bremhorst model. Numerical results were obtained for diameter ratios of 0.1, 0.2 and 0.3, and for pipe Reynolds numbers of between 80 and 60000. The computed discharge coefficients are compared with available experimental data and with the value stated in BS 1042. Results show that the model developed can predict the discharge coefficient to within ±3% for the range of diameter ratios and Reynolds numbers investigated.
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