A gas is flowing through a horizontal pipe of cross-sectional area of 30 cm². At a point the pressure is 30 N per cm² (gauge) and temperature 20°C. At another section the area of cross-section is 15 cm² and pressure is 25 N/cm² gauge. If the mass rate of flow of gas is 0.15 kg/s, find the velocities of the gas at these two sections, assuming an isothermal change. Take R = 287 J/kg K, and atmospheric pressure 10 N/cm². Leave a Comment / Fluid Mechanics, Numerical (Water) / By Shreeya Khanal / August 11, 2025
Water is flowing through two different pipes to which an inverted differential manometer having an oil of sp. gr. 0.8 is connected. The pressure head in pipe A is 2 m of water. Find the pressure in pipe B for the manometer readings as shown in the figure. Leave a Comment / Fluid Mechanics / By Ashok Sapkota / July 29, 2025
A single-acting reciprocating pump has piston diameter 15 cm and stroke length 30 cm. The centre of the pump is 5 m above the water level in the sump. The diameter and length of the suction pipe are 10 cm and 8 m respectively. The separation occurs if the absolute pressure head in the cylinder during suction stroke falls below 2.5 m of water. Calculate the maximum speed at which the pump can run without separation. Take atmospheric pressure head = 10.3 m of water. Leave a Comment / Fluid Mechanics, Numerical (Water) / By Shreeya Khanal / July 31, 2025
An oil of viscosity 5 poise is used for lubrication between a shaft and sleeve. The diameter of the shaft is 0.5 m and it rotates at 200 r.p.m. Calculate the power lost in the oil for a sleeve length of 100 mm. The thickness of the oil film is 1.0 mm. Leave a Comment / Fluid Mechanics, Numerical (Water) / By Ashok Sapkota / July 28, 2025
The surface tension of water in contact with air is given as 0.0725 N/m. The pressure outside a droplet of water of diameter 0.02 mm is atmospheric (10.32 N/cm²). Calculate the pressure within the droplet of water. Leave a Comment / Fluid Mechanics, Numerical (Water) / By Ashok Sapkota / July 28, 2025
A lawn sprinkler shown in the figure has 0.8cm diameter nozzle at the end of a rotating arm and discharges water at the rate of 12m/s. Determine the torque required to hold the rotating arm stationary. Also determine the constant speed of rotation of the arm, if free to rotate. Leave a Comment / Application of Momentum Principle, Fluid Mechanics, Numerical (Water) / By Ashok Sapkota / March 21, 2025
A metallic ball of diameter 5mm drops in a fluid of sp.gr. 0.8 and viscosity 30 poise. The sp.gr. of metallic ball is 9.0. Find (a) the force exerted by the fluid on the ball, (b) the pressure drag and skin friction drag, and (c) the terminal velocity of the ball in the fluid. Leave a Comment / Boundary layer theory, Fluid Mechanics, Numerical (Water) / By Ashok Sapkota / March 22, 2025
The stream function for a two dimensional flow is given by ψ=8xy. Find the velocity potential function. Leave a Comment / Fluid Kinematics, Fluid Mechanics, Numerical (Water) / By Ashok Sapkota / March 2, 2025
