CEE 310 Fluid Mechanics

Lab 6 Conservation of Linear Momentum

Name:________________ Lab Section:____________________ Date:_______________

Room temperature: T=_______________; Barometric pressure,= ______________

Purpose:

To apply the principle of Linear Momentum conservation to calculate the force exerted by a jet on targets of various shapes.

Equipments:

Hydraulic Bench, Impact of Jet Apparatus with a nozzle diameter

, Stop Watch.

Procedure:

1.Remove the top plate and transparent casing, measure the nozzle diameter, place the flat target on the rod attached to the weight pan. Then reassemble the apparatus.

2.Connect the inlet pipe to the bench, with the apparatus in the open channel.

3.Level the base of the apparatus with the top plate loosely assembled.

4.Screw down the top plate to datum on the spirit level.

5.Adjust the level gauge to suit the datum on the weight pan.

6.Place a nominal mass on the weight pan. Turn on the flow from the control valve on the hydraulic bench.

7.Adjust the flow rate till the weight pan is adjacent to the level gauge. When testing for level, the weight pan should be oscillated to minimize the effect of friction.

8.Record the readings of the volume and time using the hydraulic bench to find the flow rate for the assigned mass on the weight pan. Repeat for three readings.

9.Repeat the above using the hemispherical plate.

Data Recording and Calculation:

1.Flat Plate (q= 90^o)

Mass on Weight Pan	Volume of water	Time	Flow rate	Calculated Force
200.0
200.0
200.0
=(N)	Avg.=	Avg.=	Avg.=	Avg.=

1.Hemispherical Plate (q= 180^o)

Mass on Weight Pan
Volume of water
Time
Flow rate
Calculated Force

200.0

200.0

200.0

=(N)

Avg.=

Avg.=

Avg.=

Avg.=

Discussion:

How does the applied weight compare with calculated force? Please also discuss the validity of our assumptions.

Summary of Theory

Flat plate

Hemispherical plate

<![endif]>,with

This analysis neglect the decrease in velocity between the nozzle and the plate and the weight of the fluid on the plate and assumes the discharge velocity is uniform across the jet.

For flat plate (q= 90^o)

For hemispherical plate (q= 180^o)

Where: R_y =resultant force by plate on jet,

g = 9.81 m/sec²,

A = water jet discharge area, and

q = angle through which water is turned by the plate.