Hydraulics Practice
Question 1. Why when a vehicle drives on a flat road do the tyres heat up but water does not get noticeably hotter when it flows through a pipe?
Question 2. Water is flowing along a horizontal channel for a long distance. What will happen
- to the depth between the start and middle of the horizontal section ?
- What will happen to the flow velocity between the start and middle of the horizontal section?[unique_solution]
Question 3 Calculate how much potential energy there is available for electricity generation in a reservoir containing 1 million tons of water at an average height above a turbine of 50m.
Question 4
Section A Section B Section C
On the above diagram of a venturi meter show the position of the manometers assume the flow is from left to right and that the pipe is horizontal.
If the internal diameter of the pipe in sections A and C is 50mm and 25mm in section B and the pressure in section A is 400mm and 200mm in section B what is the velocity of the fluid in the pipe? The Bernoulli equation for a horizontal pipe is:
Pa + Va2/2g = Pb + Vb2/2g. Where P is pressure, V is velocity of flow and assume g = 9.81ms-2
What effect will the shape of the change in diameter between sections A and B have on the pressure readings?
Hint (hint remember Q = VA and that Q is the same through the venturi as through the rest of the pipe, and you can get the ratio of velocities between the venturi and the main pipe v1/v2 is the same as the ratio of the area of cross section of the pipes
Question 5 Reynolds Number: Re = velocity ρL/μ = velocity L/ν
where L is the length of flow or some other characteristic length μ the dynamic coefficient of viscosity N ν the kinematic coefficient of viscosity.
From this you can see that it is easier to have a low Reynolds number with a high viscosity liquid.
A pipe of length 20m has water flowing through it at a rate of 5ms-1 In this situation the L refers to the diameter of the pipe. If the pipe has a diameter of 0.1m. Calculate the Reynolds number. The dynamic viscosity μ of water at 200C is 1x 10-3Pa s The kinematic viscosity ν is the dynamic coefficient divided by the density of water approximately 1000kgm-3.