A nozzle with coefficient of velocity Cv= 0.95 is attached to the end ...
Calculation of K for a Nozzle with Coefficient of Velocity Cv=0.95
Introduction
In this problem, we need to determine the value of K for a nozzle with a coefficient of velocity Cv=0.95. The head loss in the nozzle is given by k(v^2/2g), where v is the velocity of the jet issuing from the nozzle.
Calculation of K
To calculate K, we need to use the principle of conservation of energy. The total energy of a fluid flowing in a pipe is given by the sum of its kinetic energy, potential energy and pressure energy.
At the inlet of the nozzle, the fluid has a certain amount of kinetic energy, potential energy and pressure energy. As the fluid flows through the nozzle, the cross-sectional area decreases, and the fluid velocity increases. This causes a decrease in pressure and an increase in kinetic energy.
At the exit of the nozzle, the fluid has a higher velocity and lower pressure compared to the inlet. The total energy of the fluid at the exit is given by its kinetic energy and pressure energy.
Using the principle of conservation of energy, we can write:
Total energy at inlet = Total energy at exit + Head loss
This can be expressed mathematically as:
P1/ρg + V1^2/2g + z1 = P2/ρg + V2^2/2g + z2 + k(v^2/2g)
where P1 and P2 are the pressures at the inlet and exit, respectively, ρ is the density of the fluid, g is the acceleration due to gravity, V1 and V2 are the velocities at the inlet and exit, z1 and z2 are the elevations at the inlet and exit, respectively, and v is the velocity of the jet issuing from the nozzle.
Since the nozzle has a coefficient of velocity Cv=0.95, we can write:
V2 = Cv * V1
Substituting this into the energy equation, we get:
P1/ρg + V1^2/2g + z1 = P2/ρg + (Cv * V1)^2/2g + z2 + k(v^2/2g)
Simplifying this equation, we get:
k = (P1 - P2)/ρg + (1 - Cv^2)/2
where (P1 - P2)/ρg is the static head loss and (1 - Cv^2)/2 is the dynamic head loss.
Substituting the given values, we get:
k = (0 - 0)/1000 + (1 - 0.95^2)/2
k = 0.002375
Therefore, the value of K for a nozzle with coefficient of velocity Cv=0.95 is 0.002375.
Conclusion
In this problem, we used the principle of conservation of energy to calculate the value of K for a nozzle with coefficient of velocity Cv=0.95. The value of K is a measure of the head loss in the nozzle and is important in the design of fluid systems.