Experiment No 03To Study the Flow Characteristics over a HumpDated: 17-03-2015

Objective: To study the variations in the flow with the introduction of different types of humps in the flume.

Apparatus:

(S-6) glass sided tilting Flume Apparatus Point gauge Broad crested hump Round corner Sharp corner

Sharp Edge Round EdgeRelated Theory

Hump:It is a streamline Construction provided at the bed of channel.V1Y2Y1Y3ZV2Hump

Weir:A weir is a streamlined wall or structure commonly used to raise the water level of a river or stream to divert the required amount of water into an irrigation canal. Weirs can be gated (barrage) or ungated.

Flow over a raised Hump:

Critical hump height:It is the minimum height that causes critical depth (critical flow) over the hump.(Y1- Yc)Y1YcY3Z > ZcY1> YoY1-Yo = Afflux

Z = ZcY1= Yo

Z < ZcY1= Yo

ZcZY3YcY1Y3Y2Y1Yo

Effect of hump height on depth of flow:

Procedure:

Fix the slope of the flume. Introduce round corner weir at a certain location. Set a particular discharge in the flume. Note the depth of flow at U/S, D/S and over the weir at certain points (More than one). Repeat the same for various discharges. Calculate the value of yc, y1, y2&y3 and make their comparison. Repeat the same procedure for sharp corner weir.

Comments

Observations and Calculations:

Weir TypeWidth "B"Height "Z"

mmmm

Round Cornered270120

Sharp Crested27060

Sr. #Weir TypeDischargeQ(m3/sec)Yc

(mm)Zc

(mm)Depth of flow at U/SY1(mm)Depth of Flow over the humpY2(mm)Depth of Flow at D/SY3(mm)Condition of Flow

123Avg123Avg123AvgU/SOver HumpD/S

Round cornered

Sharpcrested