Water Jet
Title
Impact of water jet
Objective
The purpose of this experiment is to demonstrate the application of the momentum equation. The force generated by a jet of water deflected by an impact surface is measured and compared to the momentum change of the jet.
To relate:
• Direct measurement of impact forces • Effect of flow rate and velocity • Effect of various deflection angles
Introduction / Theory
Newton’s Second law states that
The applied forces is equal to the rate of change of momentum
[pic]
Newton’s Second Law of Motion states that
The Applied Force is equal to the Rate of Change of Momentum.
[pic] if we assume V2 = V1 = Vy1
Where [pic] is the density of water
Vy1 is the inlet jet velocity in the y direction
Vy2 is the outlet jet velocity in the y direction
Q is the volumetric flow rate
[pic] is the angle of deflection of jet flow measured from the veritical
The negative sign means the Applied Force is opposite to the direction of the inlet jet stream.
Nozzle diameter = 8mm
Nozzle impact distance = 15mm
Bernoulli equation can be used when fluid is considered as an inviscid, incompressible and steady flow.
|[pic] | (1.4) |
With these theory and Bernoulli equation, we can determine not only the force produce by the water jet, but also the velocity of the particle in the flow.
2.1 Momentum Equations
The general momentum equation is
|[pic] | (1.5) |
where [pic] = force, [pic] = velocity, [pic] = unit outward vector on CS, which is the surface of the control volume (CV). For steady flow with a constant density, with discrete inflows and outflows, with essentially constant velocities on each inflow and outflow
Impact of water jet
Objective
The purpose of this experiment is to demonstrate the application of the momentum equation. The force generated by a jet of water deflected by an impact surface is measured and compared to the momentum change of the jet.
To relate:
• Direct measurement of impact forces • Effect of flow rate and velocity • Effect of various deflection angles
Introduction / Theory
Newton’s Second law states that
The applied forces is equal to the rate of change of momentum
[pic]
Newton’s Second Law of Motion states that
The Applied Force is equal to the Rate of Change of Momentum.
[pic] if we assume V2 = V1 = Vy1
Where [pic] is the density of water
Vy1 is the inlet jet velocity in the y direction
Vy2 is the outlet jet velocity in the y direction
Q is the volumetric flow rate
[pic] is the angle of deflection of jet flow measured from the veritical
The negative sign means the Applied Force is opposite to the direction of the inlet jet stream.
Nozzle diameter = 8mm
Nozzle impact distance = 15mm
Bernoulli equation can be used when fluid is considered as an inviscid, incompressible and steady flow.
|[pic] | (1.4) |
With these theory and Bernoulli equation, we can determine not only the force produce by the water jet, but also the velocity of the particle in the flow.
2.1 Momentum Equations
The general momentum equation is
|[pic] | (1.5) |
where [pic] = force, [pic] = velocity, [pic] = unit outward vector on CS, which is the surface of the control volume (CV). For steady flow with a constant density, with discrete inflows and outflows, with essentially constant velocities on each inflow and outflow
References: 1. A brief Introduction to FLUID MECHANICS Young | Munson | Okiishi | Huebsch. 2. web.cecs.pdx.edu/~gerry/class/EAS361/lab/pdf/lab4_impactOfJet.pdf 3. accelconf.web.cern.ch/AccelConf/e06/PAPERS/MOPCH169.PDF