Post on 28-Sep-2015
description
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