4.1 Use the Buckingham a method to develop an expression for the viscous torque T produced on a disc rotating in a liquid which depends upon the characteristic dimension D, the speed of rotation N,...

Extracted text: 4.1 Use the Buckingham a method to develop an expression for the viscous torque T produced on a disc rotating in a liquid which depends upon the characteristic dimension D, the speed of rotation N, fluid density p and absolute viscosity u. Take p, N and D as repeating variables 4.2 In order to predict the torque T on a disc 0.5 m in diameter rotating in oil at 200 rev/min, a model is made to a scale of 1/5. The model is to be rotated in water. Calculate the speed of the model which produces dynamic similarity. Note that the specific gravity of the oil is 0.75, the absolute viscosity of the oil is 0.2 Pa.s, the absolute viscosity of water is 0.001 Pa.s, and the density of water is 1000kg/m3. 4.3 Calculate the ratio of the viscous torque produced on the disc rotating in oil to the one rotating in water


Extracted text: The pressure drop across a short hollowed plug placed in a circular tube through which a liquid is flowing can be expressed as AP = 9 (p, V, D, d). Some experimental data were obtained with D = 0.1 m, p = 1000 kg/m² and V = 0.6 " as given in the following table: d (m) 0.025 0.031 0.046 0.019 A (kPa) 24 7.5 3 0.6 3.1 Use the Buckingham- theorem to develop the dimensionless parameters taking and d as repeating variables. 3.2 Plot the results of these tests using the dimensionless parameters in order to present the relationship in the form Y = ax 3. 3 Estimate the pressure drop AP in kPa if d = 0.09m.