

Characterise the flow for both the flow rates. After sometime the flow rate is increased to 3 L/min. The coefficient of viscosity of water is 10 -3 Pa s. The flow rate of water from a tap of diameter 1.25 cm is 0.48 L/min. Pressure energy per unit mass of the liquid Pressure energy of liquid in volume dV = PdV The energy possessed by a liquid by virtue of its pressure is called pressure energy. The potential energy of a liquid of mass m at a height h is given by P.E. The energy possessed by a liquid due to its motion is called kinetic energy i.e., 1/2mv 2. A liquid can possess three types of energies: (i) kinetic energy, (ii) potential energy and (iii) pressure energy Therefore, the density of the fluid is 0.445 kg per cubic m. Calculate the density of the fluid having an absolute viscosity of 0.89 N s per square m and kinematic viscosity of 2 m 2s -1 (2 marks) Due to this, there is an apparent loss in the weight experienced by the body. The upward force exerted by the liquid displaced when a body is immersed is called buoyancy. The loss in weight of the body in the liquid is equal to the weight of the liquid displaced by the immersed part of the body. When a body is partially or completely immersed in a liquid, it loses some of its weight. What is Archimedes Principle? (2 marks)Īns.

Calculate the power lost in the bearing for a sleeve length of 90 mm. The shaft is of diameter 0.4 m and rotates at 190 Rpm. The dynamic viscosity of the oil used for lubrication between a shaft and sleeve is 6 poise. Therefore, the dynamic viscosity is 1.17 NS/m 2 Therefore, Shear stress is 150/0.64 N/m 2 Therefore, the force acting along with the plane = Component of weight parallel to the plane. The weight of the square plate is 300N & it slides at a uniform velocity of 0.3m/s. Calculate the dynamic viscosity of oil, which is used for lubrication between a square plate of size 0.8m × 0.8m & an inclined plane with an angle of inclination of 30°. Since this is below 1000, the flow is steady. We then estimate the Reynolds number to be The volume of the water flowing out per second is Let the speed of the flow be v and the diameter of the tap be d = 1.25 cm. After some time the flow rate is increased to 3 L/min. Therefore it is clear that Mercury fluid will correspond with this fluid. First calculate the dynamic viscosity using the following formula, using the given values, According to its dynamic viscosity, to which one of these fluids corresponds? (3 marks)Īns. A fluid with a shear rate of 0.5 per second, and the shearing stress 0.76 N per m 2. Therefore, dynamic viscosity can be expressed as the tangential force per unit area required to move the fluid in a horizontal plane relative to another plane, with a unit value velocity while the molecules of the fluid maintain a distance unitary each on the other. Therefore, dynamic viscosity is the force required for fluid to overcome its internal molecular friction so that the fluid can flow. Viscosity acts as an important property of fluid when analyzing fluid behaviour and fluid movement near solid limits. It is a type of tangential force that acts when one horizontal plane moves with another. The dynamic viscosity formula for the fluid will define its internal resistance to flow due to shear force. Shear stress in the fluid is possible due to the intermolecular friction exerted when layers of fluids attempt to flow over each other. The viscosity of a fluid is the measure of the resistance to its progressive deformation by traction or shear.
