FLUID MECHANICS
Fluids mechanics is a branch of mechanics that is concerned with properties of gases and liquids. Mechanics is important as all physical activities involves fluid environments, be it air, water or a combination of both.

The type of fluid environment we experience impacts on performance.

Flotation
The ability to maintain a stationary on the surface of the water- varies from he on person to another. Our body floats on water when forces created by its weight are matched equally or better by the buoyant force of water. For an object to float it needs to displace an amount of water that weighs more than itself. Body density, or its mass per unit volume, also impacts on the ability to float. Density is an expression of how tightly a body’s matter is enclosed within itself.

Centre of buoyancy
If our average total body density is higher than that of water, we sink but this does not happen uniformly. Every floating object has a centre of gravity and centre of buoyancy. We saw on page 223 that the centre of gravity is the point around which the body’s weight is equally balanced in all directions. The centre of buoyancy is the centre of gravity of the fluid displaced by a floating object. Around this point, all the buoyancy forces are balanced

Fluid resistance
When a body or object moves, whether it be in air or water, it exerts a force and simultaneously encounters a resisting force from that medium.In sporting competitions such as swimming and athletics, drag and lift forces are constantly responding to the object or body’s thrust. There are many types of forces exerted by fluids that resist an implement or body trying to move through it. At the same time, technological improve- ments have enabled us to better use the specific fluid to decrease resistance; for example, better configuration of the dimples on a golf ball can improve its flight performance. Drag is the force that opposes the forward motion of a body or object, reducing its...

...ENT 310 FluidMechanics Midterm #1 – Open Book and Notes
Name _______________________
1. (5 pts) The maximum pressure that can be developed for a certain fluid power cylinder is 50.0 MPa. Compute the force it can exert if its piston diameter is 100 mm.
2. (5 pts) Calculate the weight (in Newtons) of 100 liters of fuel oil if it has a mass of 900 Kg.
3. (5 pts) The fuel tank of a truck holds 0.20 cubic meters. If it is full of gasoline having a specific gravity of 0.68, calculate the weight of the gasoline.
4. (10 pts) A cylindrical container has a 12 in. diameter and weighs 1.50 lbs when empty. When filled to a depth of 10.0 inches with a certain oil, it weights 46.9 lb. Calculate the specific gravity of the oil.
ENT 310 FluidMechanics Midterm #1
Page 1
ENT 310 FluidMechanics Midterm #1 – Open Book and Notes
Name _______________________
5. (5 pts) Define the term terminal velocity as it applies to a falling ball viscometer.
6. (5 pts) Convert a viscosity measurement of 7.8 x 10-4 Pa-s to the units of lb-s/ft2.
7. (10 pts) In a falling ball viscometer, a steel ball with a diameter of 0.25 inches is allowed to fall freely in a heavy fuel oil having a specific gravity of 0.86. Steel weighs 0.283 lb/in3. If the ball is observed to fall 12.00 inches in 10.4 seconds, calculate the dynamic viscosity of the oil in lb-s2/ft.
ENT 310...

...Fluid Report 2
In the derivation of Bernoulli’s equation, the assumption of the inviscid and incompressible flow is used. However in the real case, the viscosity cannot be neglect and the density of the flow is not always constant. Thus Bernoulli’s equation is not always correct. For the lab, it is reasonable to assume the flow is inviscid and incompressible. Firstly, the pitot was placed at the center of the flow. The skin friction (effect of viscosity) is inversely proportional to distance. Therefore the effect of viscosity can be neglected in the pitot. Secondly, the speed of the flow is much lower than the speed of sound under the sonic condition. Therefore, the Mach number is low enough to neglect the change of density of the controlled volume and the controlled volume is almost incompressible. That is why we can estimate the velocity of the flow by Bernoulli’s equation and continuity equation.
As a result of the viscosity, the internal flow is constrained by the bounding walls and the effect grows during the entire flow. At the inflow region, the flow is nearly inviscid. After that, the boundary layers are growing along the duct which is called developing profile region. This is because the effect of viscosity is growing. At the centre of the duct, there is an inviscid core flow. When the boundary layers are merged, the flow is fully developed and the velocity is not affected by viscosity anymore. Meanwhile the static pressure decreases due...

...Class: DME2
Title: Flow Measurement
Date: 11/02/2013
Lecturer: Mr Higgins
Summary:
In this experiment many different meters were used to measure fluid flow rate; the orifice plate, the venture meter, the rota meter and the weigh tank. Each meter works by its ability to alter a certain physical property of the flowing fluid and then allows this alteration to be measured. The measured alterations are linked directly to the flow rate and these measurements are subbed in to adjusted equations to solve for it. Each methods outcome is then analysed, compared against each other.
1. Objectives:
* To introduce the student to three typical methods of measuring he flow rate of an incompressible fluid namely;
1- Venturi metre
2- Orifice plate
3- Rotor metre
* To compare the accuracy of each device.
* To give insight into appropriate industrial application for each device.
2. Theory:
Water enters and first flows through the Venturi metre, then through the Orifice plate and then through the Rotor meter. On leaving the Rotor meter the water flows via a control valve to the weigh-tank of the hydraulic bench. At the inlet and the outlet of each flow measuring device is a connection to the manometer board, this allows the head loss to be determined across each device.
For an incompressible fluid flowing through a pipe the following equations apply:
Continuity, Q=V1A1=V2A2 (1)...

...FluidMechanic Lab Layout
Name Of Apparatus
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. Door Door Bernoulli’s Theorem White Board Green Board Students Chairs Teacher Table Turbine Service Unit Axial Fan Centrifugal Fan Cavitations Demonstration Vin Tunnel Fluid Particle System Centrifugal Pump (Computer Control) Water Hammering Losses in Pipes Multi Pumps ( Computer Control ) Nozzle Performance Unit Losses in Bends Flow Meter Demonstration Orifice And Free Jet Flow Orifice Discharge Osborne-Reynolds Impact Of Jet Flow Visualization in Channel Free And Force Vortices Metacentric Height Pelton Turbine Series and Parallel Pumps Black Board
FLUIDMECHANICS-I
HYDRAULIC BENCH-FME 00
1.OBJECTIVE To study the Hydraulic Bench
OSBORNE REYNOLDS DEMONSTRATION-FME 06
1.OBJECTIVE To observe laminar, transition and turbulent pipe flow. 2.OBJECTIVE Study of the velocity profile, reproducing the Osborne-Reynolds’s experiment 3.OBJECTIVE To calculate Reynolds’s number.
IMPACT OF JECT-FME 01
1.OBJECTIVE To investigate the reaction force produced by the change in momentum of a fluid flow
ENERGY LOSSES IN BENDS-FME 05
1. OBJECTIVE To determine the loss factors for flow through a range of pipe fittings including bends, a contraction, an enlargement and a gate-valve
ORIFICE AND FREE JET FLOW-FME 17
1. OBJECTIVE To...

...gage pressure. Pgage = Pabs - Patm
The pressure at a point in a fluid has the same magnitude in all directions. (Pressure is a scalar)
Variation of Pressure with Depth
It will come as no surprise to you that pressure in a fluid at rest does not change in the horizontal direction. This can be shown easily by considering a thin horizontal layer of fluid and doing a force balance in any horizontal direction. However, this is not the case in the vertical direction in a gravity field. Pressure in a fluid increases with depth because more fluid rests on deeper layers, and the effect of this “extra weight” on a deeper layer is balanced by an increase in pressure
For a given fluid, the vertical distance \Delta z is sometimes used as a measure of pressure, and it is called the pressure head.
If we take the top of a fluid to be at the free surface of a liquid open to the atmosphere, where the pressure is the atmospheric pressure Patm, then the pressure at a depth h from the free surface is: P = Patm + \rho *gh or Pgage = \rho *gh
Liquids are essentially incompressible substances, and thus the variation of density with depth is negligible. This is also the case for gases when the elevation change is not very large. at great depths such as those encountered in oceans, the change in the density of a liquid can be significant because of the compression by the tremendous...

...Experiment 3: Fluid Flow Friction and Fitting Loss
Objective
To determine the pressure or head loss in different diameters pipes, joints and valves
Theory
Pipe flows belong to a broader class of flows, called internal flows, where the fluid is completely bounded by solid surfaces. In contrast, in external flows, such as flow over a flat plate or an airplane wing, only part of the flow is bounded by a solid surface. The term pipe flow is generally used to describe flow through round pipes, ducts, nozzles, sudden expansions and contractions, valves and other fittings. When a gas or a liquid flows through a pipe, there is a loss of pressure in the fluid, because energy is required to overcome the viscous or frictional forces exerted by the walls of the pipe on the moving fluid. In addition to the energy lost due to frictional forces, the flow also loses energy (or pressure) as it goes through fittings, such as valves, elbows, contractions and expansions. This loss in pressure is mainly due to the fact that flow separates locally as it moves through such fittings. The pressure loss in pipe flows is commonly referred to as head loss. When a fluid flows through pipes, energy is lost inevitably due to frictions which occur as a result of viscous drag. Fluid friction produces eddies and turbulence, and these form of kinetic energy are eventually converted into thermal energy. Losses in...

...value of the loss coefficients can be used (to be verified). 4 The elevation difference between the free surfaces of the tank and the river remains constant. 5 The effect of the kinetic energy correction factor is negligible, = 1. Properties The density and dynamic viscosity of water at 70 F are 6.556 10-4 lbm/ft s. The roughness of galvanized iron pipe is = 0.0005 ft. = 62.30 lbm/ft3 and = 2.360 lbm/ft h =
Analysis The piping system involves 125 ft of 5-in diameter piping, an entrance with negligible loses, 3 standard flanged 90 smooth elbows (KL = 0.3 each), and a sharp-edged exit (KL = 1.0). We choose points 1 and 2 at the free surfaces of the river and the tank, respectively. We note that the fluid at both points is open to the atmosphere (and thus P1 = P2 = Patm), and the fluid velocity is 6 ft/s at point 1 and zero at point 2 (V1 = 6 ft/s and V2 =0). We take the free surface of the river as the reference level (z1 = 0). Then the energy equation for a control volume between these two points simplifies to
P1 g
1
V12 2g
z1
h pump, u
P2 g
2
V 22 2g
z2
h turbine, e
hL
1
V12 2g
h pump, u
z2
hL
where
1
= 1 and
V2 L h L h L ,total h L ,major h L ,minor f KL 2 D 2g since the diameter of the piping system is constant. The average velocity in the pipe and the Reynolds number are V Re V Ac VD V D2 / 4 1.5 ft 3 /s (5 / 12 ft) 2 / 4
3
2
5 in 125 ft 12 ft
Water tank
11.0 ft/s
1...

...correctly answered: c. vessel radius.
2. Vessel radius and fluid flow
You correctly answered: b. are directly proportional.
3. After a heavy meal, when we are relatively inactive, we might expect blood vessels in the skeletal muscles to besomewhat __________ and the blood vessels in the digestive organs to be somewhat __________. You correctly answered: d. constricted, dilated
4. When you increased the flow tube radius, the fluid flow rateYou correctly answered: a. increased.
Review Sheet Results
1. Explain how the body establishes a pressure gradient for fluid flow.
Your answer:
The body establishes a pressure gradient for fluid due to the pressure difference between the two ends of the vessel.
2. Explain the effect that the flow tube radius change had on flow rate. How well did the results compare with yourprediction? Your answer:
I predicted that the flow would increase if the radius was increased. It is true since the low rate is directly proportional with the flow tube radius meaning the bigger the radius of the flow tube the faster the flow rate and vice versa. It is also evident during the experiment since the flow rate increased each time that we increased the radius.
3. Describe the effect that radius changes have on the laminar flow of a fluid.
Your answer:
The radius of the flow tube affects the laminar flow of a fluid since the wider the radius the more freely the...