Experiment 1
Fluid Flow In A Smooth Pipe
Abstract
In this experiment, three variable flow meters are used to alter the flowrate. Changes in pressure drop due to the change in flowrate are then observed from the three pressure gauges that can measure pressure at different range and recorded. The shift from laminar flow to turbulent flow is seen from the results recorded, but it is observed more clearly from the water-soluble dye experiment that was carried out by the demonstrator. Laminar flow turns to be turbulent when the Reynolds Number goes above a certain value, around 2000.

Aims
To look at how the pressure drop changes when the average velocity is altered in a circular pipe and to plot a graph of Friction Factor versus Reynolds Number. Another aim is to examine the shift from laminar flow to turbulent flow.

Schematic Diagram
Water Out
Inverted Water-air Manometer
Wet-wet Digital Differential Pressure (0-100kPa)
Capsuhelic Differential Pressure (0-250kPa)
1600 L/hr
250 L/hr
70 L/hr
1.5m
Water In
water-soluble dye
P
P

P

Figure 1: Schematic Diagram of Apparatus Used and Direction of Flow in a Smooth Pipe

Results
A graph of log - log plot of f versus Re is plotted, and a straight line of best fit through the data points for laminar flow is drawn:

Figure 2: Graph of log - log plot of f versus Re

Discussions
To calculate the slope of the best fit line from Figure 2, two points are selected: (600, 0.02) and (200, 0.07) slope=log(0.02)-log(0.07)log600-log(200)
slope=-1.14
Theoretically, in the laminar flow regime for pipe flow,
f=16Re
logf=log(16Re)
logf=log16-log(Re)
logf=-logRe+1.2
So, we expect the value of the slope to be -1. In Figure2, the slope found is -1.14, which is close to -1. Both values agree with each other. At the maximum flowrate, Q = 1600L/hr = 4.44 x 10-4 m3/s

The parameters:
d=0.0126 m ρ=999.44 kg/m3 μ=0.001222 kg/ms Sample calculation to...

...any pipe system there is going to be a loss of energy due to the effect of viscosity from a fluid acting upon the surface of the pipe, this is called Friction Loss. This type of lost depends on the shear stress due to the walls of the pipe and the fluid. It also depends in weather the fluid is laminar or turbulent.
A major difference between these two flows is that due to a viscous layer created in turbulent flow the roughness of the pipe can be taken in account while in laminar flow, it can be neglected because that layer is not created. Many factors are taken in account when we want to measure the energy lost during the trajectory of a fluid through a pipe such as, distance, diameter, roughness of the surface, viscosity of the fluid, all affect friction loss. However, many of the aforementioned factors are considered “minor loss,” but friction loss is considered a “major loss.”
The frictional resistance to which a fluid is subjected, as it is moving along a pipe it continuously losses energy going downstream. The mean velocity in the pipe (remains constant) the friction factor f is defined by
And the Reynolds number can be obtained by
For typical flows in smoothpipes, laminar flow...

...Experiment 3: FluidFlow Friction and Fitting Loss
Objective
To determine the pressure or head loss in different diameters pipes, joints and valves
Theory
Pipeflows 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 pipeflow 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 pipeflows is commonly referred to as head loss. When...

...No. 5
CLASSIFICATION OF FLUIDFLOW AND THE CONTINUITY EQUATION
5.1 Classification of FluidFlow
Uniform flow
If the velocity of the fluid is the same in magnitude and direction at every point in the fluid the flow is said to be uniform.
Non-uniform flow
A non-uniform flow is one where the velocities at different points at a given instant are not the same. Every fluid that flows near a solid boundary will be non-uniform because the fluid at the boundary takes the velocity of the boundary which is usually zero.
Steady flow
A steady flow is one in which the conditions (i.e., velocity, pressure, cross-section) may vary from point to point but do not change with time.
Unsteady flow
If at any point in the fluid, the conditions change with time, the flow is unsteady. In reality, there are always slight variations in velocity and pressure; however, if the average values are constant, the flow may be considered steady.
Steady uniform flow
In steady uniform flow, conditions do not change with position in the stream or with time.
Example: Flow of water in a pipe of constant diameter at constant velocity
Steady non-uniform flow...

...Laminar and Turbulent FluidFlows:
If you’ve ever traveled on an airplane, you might recall the pilot instructing you to fasten your seat belt because of the turbulence associated with severe weather patterns or airflow over mountain ranges. You may also have had other firsthand experiences with laminar and turbulent fluidflows. Try opening the valve on a garden hose (without a nozzle) by just a small amount, and watch how water streams out of it in an orderly fashion. The shape of the water stream doesn’t change much from moment to moment, which is a classic example of laminar water flow. As you gradually open the valve, you’ll eventually reach a point where the smooth stream of water starts to oscillate, break up, and become turbulent. What was once glassy-looking water is now disrupted and uneven. In general, slowly flowing fluids appear laminar and smooth, but, at a high enough speed, the flow pattern becomes turbulent and random-looking. When fluidflows smoothly around an object, as in the sketch of airflow around a sphere, the fluid is said to move in a laminar manner. Laminar flow occurs when fluid is moving relatively slowly. As fluid moves faster past the sphere, the flow’s pattern begins to break up and become random, particularly on the sphere’s...

...f NHYDRAULICS 1 (HYDRODYNAMICS)
SPRING 2005
Part 1. Fluid-Flow Principles
1. Introduction
1.1 Definitions
1.2 Notation and fluid properties
1.3 Hydrostatics
1.4 Fluid dynamics
1.5 Control volumes
1.6 Visualising fluidflow
1.7 Real and ideal fluids
1.8 Laminar and turbulent flow
2. Continuity (mass conservation)
2.1 Flow rate
2.2 The steady continuity equation
2.3 Unsteady continuity equation
3. The Equation of Motion
3.1 Forms of the equation of motion
3.2 Fluid acceleration
3.3 Bernoulli’s equation
3.4 Application to flow measurement
3.5 Other applications (flow through an orifice; tank-emptying)
4. The Momentum Principle
4.1 Steady-flow momentum principle
4.2 Applications (pipe contractions; pipe bends; jets)
5. Energy
5.1 Derivation of Bernoulli’s equation from an energy principle
5.2 Fluid head
5.3 Departures from ideal flow (discharge coefficients; loss coefficients; momentum & energy coefficients)
Part 2. Applications (Separate Notes)
1. Hydraulic Jump
2. PipeFlow (Dr Lane-Serff)
Recommended Reading
Hamill, 2001, Understanding Hydraulics, 2nd Edition, Palgrave, ISBN 0-333-77906-1
Chadwick, Morfett and Borthwick, 2004, Hydraulics in Civil and Environmental...

...Chapter 11 Flow in Closed Conduits
CN2122 / CN2122E
Main Topics
• • • •
Introduction
Reynolds' Experiment Dimensional Analysis of Conduit Flow Friction Factor for Fully Developed Laminar Flow Friction Factor for Fully Developed Turbulent FlowSmoothPipe Law Rough Pipe Law Different Workers Results Application
Energy/ pressure loss problem Velocity/flow rate problem Pipe Sizing Problem
•
Explicit Equation for Friction Factor
CN2122 / CN2122E
Main Topics
• • •
Equivalent Diameter for Non- Circular Conduit Pressure Drop due to Fittings Loss of Head at Abrupt Enlargement
Exit Loss Loss of Head at abrupt Contraction Entry Loss
Combinations of Pipes
CN2122 / CN2122E
11.0 Introduction
In this chapter, we will go back to consider what we have left out in Chapter 7- viscous work done term. Because of this, this chapter is quite important for it is dealing with real practical problems. For chemical engineers, more than 90% of their problems involve flows in closed conduits.
CN2122 / CN2122E
11.1 Reynolds' Experiment
The classic Reynolds experiment on viscous flow was conducted in 1883. Water is made to flow through a glass pipe as shown in Fig.11.1.1, the velocity being controlled by an outlet valve. At the...

...FLOW MEASUREMENT (Venturi meter, Orifice Plate and Rotameter)
OBJECTIVES To study the characteristics and applications of various flow measuring device (venturi meter & orifice plate). To calculate the volume flow rate of water from the pressure difference of both venturi and orifice devices. To compare between theoretical and actual volumetric flow rate through the discharge coefficient concept. To know how rotameter works.
INTRODUCTION The measurement of fluidflow is important in applications ranging from measurements of blood-flow rates in human artery to the measurement of liquid oxygen in a rocket. The selection of the proper instrument for a particular application is governed by many variables, including cost. Flow-rate-measurement devices frequently require accurate pressure and temperature measurements in order to calculate the output of the instrument. The most widely used flow metering principle involves placing a fixed area flow restriction of some type in the pipe or duct carrying the fluid. This flow restriction causes a pressure drop that varies with the flow rate. Thus, measurement of the pressure drop by means of a suitable differential-pressure pick up allows flow rate measurement. Each of the flow measurement devices inherently...

...The main objective of this assignment is to simulate a 3-D air flow in a pipe using Ansys CFX. The pipe was simulated under specific conditions. These conditions are air temperature to be 25⁰C (degrees Celsius), one atmospheric reference pressure, no heat transfer and laminar flow. The results from the simulation of laminar flow in the pipe were compared with the theoretical ones. Also the mesh was refined in the simulation to see if it is possible to get more accurate results using grid convergence analysis.
Method:
The pipe used in the simulation has dimensions of a 0.5m axial length and a radial diameter of 12mm. The air entering the pipe, inlet velocity, is set to 0.4 m/s at a temperature of 25⁰C and one atmospheric pressure. No slip condition was set on the pipe walls. The outlet of pipe was set to zero gauge average static pressure. In CFX a mesh was formed on the pipe with a default mesh spacing (element size) of 2mm. Figure (1) and (2) shows the setup of the model before simulation was preformed
Figure 1: Mesh without Inflation
Figure 1: Mesh without Inflation
Figure 2: Mesh with Inflation
Part 2
Calculating the pressure drop Δp=fLDρ Ub22 Equation (1)
Calculating Reynolds number Re=UbD/μ Equation (2)
Friction Factor f=64/Re Equation (3)
The...