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GATE, PSUs - Hydraulics, Irrigation, water resource Engg. notes - part 9

Hello there,
How have you been? Here is the 9th part of our notes for preparation of GATE and other examinations related to Civil Engineering.

  1. The displacement thickness of a boundary layer is the distance by which the main flow is to be shifted from the boundary to maintain the continuity equation.
  2. The range of specific speeds in MKS units for Francis turbine is 60-300, for Kaplan turbine is 300 - 1000; for Pelton with one jet is 10-35 and for Pelton with two jets is 35-60.
  3. If the height of submerged portion of a symmetrical right circular cone is 'h', then the centre of buoyancy will be at a height of 3/4(h) from the apex on the bottom side.
  4. Loss of head for various pipe fitting is given by (K.v^2)/(2g). The value of K in will be in increasing order for the following sequence of fitting: 45 degree elbow, 90 deg. elbow, foot valve of pump and close return bend.
  5. In a pipe network at a point, if a pipe diverges into two other pipes of smaller diameters and if those two again converge into one at another point, then the potential drop between these two points will be same for both of the pipes.


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Comparison of Kennedy's and Lacey's Theories

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Here is a brief comparison of Kennedy's theory and Lacey's theory for the design of channels for canal etc.

The concept of silt transportation is same in both the cases, both agree that the silt is carried by the vertical eddies generated due to friction of the flowing water against rough surface of canal. Kennedy considered a trapezoidal channel section and, therefore, he neglected eddies generated from the sides. For this reason, Kennedy's critical velocity formula was derived only in terms of depth of flow(y).  Lacey considered that an irrigation channel achieves a cup-shaped section(semi-ellipse) and that entire wetted perimeter of the channel contributes to the generation of silt supporting eddies. He, thus, used hydraulic mean radius(R) as a variable in his regime velocity formulas instead of depth(y).Kennedy stated all the channels to be in state of regime provided they did not silt or scour. But Lacey differentiated between two regime conditions, i.e. initia…

GATE, PSUs - Hydraulics, Irrigation, water resource Engg. notes - part 7

Hello there,
How have you been? Here is the 7th part of our notes for preparation of GATE and other examinations related to Civil Engineering.

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GATE questions from Hydrology - GATE PSUs preparation -part 10

Hi,
Here are few statements from Hydrology which has made their place in GATE Civil Engineering(CE). The bold letter represents the answer which are absent in actual question.

A linear reservoir is one in which storage varies linearly with outflow rate.When there is an increase in the atmospheric pressure, the water level in a well penetrating in a confined aquifer does not undergo any change.During a 6-hour storm, rainfall intensity was 0.8 cm/hour on a catchment of area 8.6 km^2. The measured runoff volume during this period was 2,56,000 m^3. The total rainfall that was lost due to infiltration, evaporation, and transpiration (in cm/hour) is 0.304.Vertical hydraulic conductivity of the top soil at certain is 0.2 cm/hr. A storm of intensity 0.5 cm/hr occurs over the soil for an indefinite period. Assuming surface drainage to be adequate, infiltration rate after the storm has lasted for a very long time, shall be 0.2 cm/hr.While applying Rational formula for computing design discharge, …