Transport Phenomena
Answer the following in brief (10 x 2) What are the factors on which viscosity depends? The viscosity of the liquid increases if the density of the liquid increases. We know that the density of the liquid decreases as the temperature increases and hence viscosity also decreases. So we can say that the viscosity of liquid depends on both density and temperature both. Differentiate between free and wall turbulence. Turbulence can be generated in two ways: (1) by friction forces at solid walls (or surfaces) and (2) by the flow of fluid layers with different velocities past the other. These two types of turbulence are, respectively, known as wall turbulence and free turbulence. What is ‘The Von Karman analogy? Von Karman extended Prandtl’s analogy by separating the flow field into three distinct layers: a viscous sublayer, a buffer layer, and a turbulent core. In the buffer layer, molecular and eddy diffusivities are assumed to be of the same order of magnitude. The physical signifi