FD Fluid Mechanics - Lab Report Example

FD Fluid Mechanics Student Name: Student ID: Course: Lecturer: Date of submission: TABLE OF CONTENTS Introduction 4 Studying Polis 5 Task 2 5 Running Tutorials: 5 Turnaround Duct Flow 7 Brief of the CFD Laboratory: 7 Conclusion 11 References: 11 Introduction In this report, we will be able to learn and understand computational fluid dynamics, CFD and its description on numerical codes that help in determining the fluid properties like temperature, pressure, chemical composition and velocity. Additionally, this report provides answers relating to understanding phoenics library exploration; studying polis; flow in a duct in a turnaround and running tutorials. In the event of studying this report, students will be in position to understand phoenics as well understanding how effective and efficient the system can operate. In the phoenics process exploration, one will be in a position to explore phoenics, where in this case, pressure distribution, pressure distribution and view angles are of importance. From the tutorials, we are able to work and analyse on the retribution results. In fluid process flow, it is critical to understand that, fluid flow is dependent on the condition of the duct and is important for modelling and analysis. As the term PHOENICS stands, it means Parabolic Hyperbolic of Elliptic Numerical Integration Code Series. It is therefore a general software used in analysis and understanding on how fluids like water, air, steam and flow in engines. In addition, this system is important when analysing physical and chemical composition. Quite a number of professional engineers and scientists apply PHOENICS when designing and making project plans. These projects may involve architectural designs for buildings, and engineering power designs. On the other hand, environmental specialists use phoenics in studying and controlling the environmental impacts as well as hazards. Deliver their jobs for example interpretation of experimental observations by scientists. Studying Polis To answer the study questions on turbulence and boundary conditions, there were three consecutive mathematical models used and they were based on the studies. Task 2 The inlet fluid goes into the system with consideration of the system inlet conditions. This flow is through domains towards the direction of the flow vector. During this continued flow process and as the fluid passes the domain wedge, it is guided to follow the colour, where the red section indicates velocity increase. On the other hand, the as the cross sectional domain decreases, the domain shift to the section with lowest cross-sectional area where it attains maximum velocity. The wedge size decreases as the flow continues, this way the cross-sectional area increases, decreasing the velocity along flow pipes until flow velocity in equalized in the entire system. Using the Bernoulli principle, it is clear that fluid flow velocity increases this in turn it was started by Bernoulli. Therefore, it should be understood that, constriction of the flow path reduced the Ericson system on energy density. Running Tutorials: In this paper, we are developing a clear understanding to the readers to develop a analytical basis of the array creating duplicates as well as studying the surrounding under which the Phoenics operate. Moreover, this guide will help in duplicating one object and producing numerous arrays that relate to the same object. One cylinder was developed using the VR while the other five cylinders were made replicas using the array function. In this system, a velocity of 0.1ms-1, which was based on turbulence model. It is appropriate to use cylinders since it gives uniform stream. This is because it has been divided into opposing directions, where one flow under one cylinder and the other flows over the second cylinder. The two flows are connected such that they pass through downstream of the cylinder and their flow is symetric and made with respect to the X-axis. The section with high pressure is made infront od the cylinder, which is careated by stagnation point towards the surface that is near to it due to collinding flows into the cylinder. A second stagnation point is created at the section where the flow from the cylinder, which is on the trailing surface. The two fluids flowing in the same direction below and above the stagnation point around cylinder meet at the trailing stagnation point. However, as the fluids move forward an enlargement space is created making the velocity constant thus making it normal flow. On the other hand, as the cylinder outlet narrows, velocity of the flowing fluids increases. Similarly, as the space of the exit is reduced creates a restriction to the flow thus creating flow acceleration. As the separation of the two fluid increase between the bottom and the top corners, this reduces the velocity at those points. This separation of the flow it develops a reverse flow that produces flow eddies that are in the reverse. Due to these differences, there is significantly low-pressure difference. Turnaround Duct Flow Brief of the CFD Laboratory: Investigate the properties of the flow for the absolute values of the inlet velocities in the range from 0.001 m/s to 100 m/s. Choose the laminar of turbulent (k - e) models depending on the value of the Reynolds number of the flow. Compare the predictions of turbulent and laminar models in the transitional regime. Then to describe the main properties of the flow and link your observations with lecture material where appropriate. Douglas, et al, (2001) states that 20˚C is the room temperature and that 101.325 kPa is the atmospheric pressure while 1m is the tube diameter and based on temperature and pressure, 15.13 x 10-6 kinematic Viscosity of air. It is easy to determine if the flow is turbulent or laminar by the use of Reynolds number (). Using the Reynolds number, if, the flow is said to laminar and if Reynolds number, then, the flow is turbulent and if the flow is more than 4000 it is turbulent flow. The following equation was used to get the Reynolds number: Where: - Reynolds Number Fluid Density Fluid flow velocity (based on the actual cross section area of the duct or pipe) Dynamic viscosity Characteristic length Kinematic viscosity The table below is used to help in investigating inlet velocities range from 0.001m/s to 100 m/s and it compares the turbulent and laminar flows of the fluid using Reynolds number. Velocity (m/s) Length (m) Kinematic Viscosity Reynolds Number Type Of Flow 0.001 1 0.00001513 66.09385327 66 < 2300 Laminar flow 0.005 1 0.00001513 330.4692664 330 < 2300 Laminar flow 0.01 1 0.00001513 660.9385327 661 < 2300 Laminar flow 0.035 1 0.00001513 2313.284865 2300 < 2313 > 4000 Transition flow 0.05 1 0.00001513 3304.692664 2300 < 3305 > 4000 Transition flow 0.1 1 0.00001513 6609.385327 6609 > 4000 Turbulent flow 0.5 1 0.00001513 33046.92664 33047 > 4000 Turbulent flow 1 1 0.00001513 66093.85327 66094 > 4000 Turbulent flow 5 1 0.00001513 330469.2664 330469 > 4000 Turbulent flow 10 1 0.00001513 660938.5327 660939 > 4000 Turbulent flow 50 1 0.00001513 3304692.664 3304693 > 4000 Turbulent flow 100 1 0.00001513 6609385.327 6609385 > 4000 Turbulent flow Table 1: inlet velocities comparison Laminar model Figure 1: Pressure distribution at Velocity of 0.001 m/s The figure above shows the fluid flow tube in which it enters from the bottom of the tube at a constant pressure and the inlet velocity at which the fluid enters the tube is 0.001 m/s. As the fluid approaches the tube curvature, low-pressure builds up at the inside part at this section indicated by blue region of the scale and as a result, there is an increase in air velocity at this region. Consequently, at this point of the pipe there is a higher pressure that is developed from the external part of the pipe curvature, which is indicated using the red section from fig 1 above. Due the pressure differences on the inside and the outside sections, velocity of the air slows down. As a result of the differences, it clear that the entire pressure at the upper section exiting the tube is lower than pressure at the tube entrance. This change in pressure differences creates higher flow velocities the exit section. The condition of the flow creates shear forces and viscosity at the boundary surface while opposing the fluid flow making it laminar flow. At the boundary section, the shear forces are greater and therefore, they create resistance to the flow of the fluid. To investigate this, we used 0.001 m/s as the determinant velocity. Turbulent model Figure 2: Pressure distribution (Velocity = 100 m/s) The inlet velocity in this section of the pipe is 100m/s, while Reynolds number used is 6609385. Therefore, this make the flow turbulent. All the sections of the entire flow indicate uniformity in flow giving pressures that high and low in entire system, which brings about varying turnaround duct velocities. These velocities are either fast or slow. For distribution of the pressure in the higher-pressure sections varies to lower pressure on the outer section of the curve, which results into increased and faster velocity at the upper tube exiting the tube shown in the figure above. Increase of the Reynolds number 6609385 in the region of turbulent flow and the velocities seemed to be same showing the only changes in the flow velocities at the outer sections of the curvature. The corresponding inlet fluid flow velocity of 0.035m/s has a critical Reynolds number of 2300. This Reynolds number is critical and provides a transition phase to turbulent flow from laminar making the velocity is critical. It becomes more complicated when the flow has a drag coefficient that affects the behaviour of the flow making the flow to appear as pure laminar or turbulent. In eddy viscosity () of the turbulent flow is directly proportional to drag coefficient, this is also directly proportional to the given Reynolds number. Hence, raising the Drag coefficient it results to an increase in the Reynolds number, which in turn raises turbulent flow drag coefficient. Conclusion In the CFD software, Phoenics gives the user the ability to understand and calculate the pressures and velocity differences in the flow. In addition, it enables the user to learn how to develop and create imitational images that brings changes and the effects that fluid has on the system. From the design functions, the user is able to distinguish between the possible functions that are desired in helping the considerations that are desired. References: Douglas, F., Gasiorek, M and Swaffield, A (2001). Fluid Mechanics. 4th ed. Edinburgh: Pearson Education Limited. 897. Read More

This is because it has been divided into opposing directions, where one flow under one cylinder and the other flows over the second cylinder. The two flows are connected such that they pass through downstream of the cylinder and their flow is symetric and made with respect to the X-axis. The section with high pressure is made infront od the cylinder, which is careated by stagnation point towards the surface that is near to it due to collinding flows into the cylinder. A second stagnation point is created at the section where the flow from the cylinder, which is on the trailing surface.

The two fluids flowing in the same direction below and above the stagnation point around cylinder meet at the trailing stagnation point. However, as the fluids move forward an enlargement space is created making the velocity constant thus making it normal flow. On the other hand, as the cylinder outlet narrows, velocity of the flowing fluids increases. Similarly, as the space of the exit is reduced creates a restriction to the flow thus creating flow acceleration. As the separation of the two fluid increase between the bottom and the top corners, this reduces the velocity at those points.

This separation of the flow it develops a reverse flow that produces flow eddies that are in the reverse. Due to these differences, there is significantly low-pressure difference. Turnaround Duct Flow Brief of the CFD Laboratory: Investigate the properties of the flow for the absolute values of the inlet velocities in the range from 0.001 m/s to 100 m/s. Choose the laminar of turbulent (k - e) models depending on the value of the Reynolds number of the flow. Compare the predictions of turbulent and laminar models in the transitional regime.

Then to describe the main properties of the flow and link your observations with lecture material where appropriate. Douglas, et al, (2001) states that 20˚C is the room temperature and that 101.325 kPa is the atmospheric pressure while 1m is the tube diameter and based on temperature and pressure, 15.13 x 10-6 kinematic Viscosity of air. It is easy to determine if the flow is turbulent or laminar by the use of Reynolds number (). Using the Reynolds number, if, the flow is said to laminar and if Reynolds number, then, the flow is turbulent and if the flow is more than 4000 it is turbulent flow.

The following equation was used to get the Reynolds number: Where: - Reynolds Number Fluid Density Fluid flow velocity (based on the actual cross section area of the duct or pipe) Dynamic viscosity Characteristic length Kinematic viscosity The table below is used to help in investigating inlet velocities range from 0.001m/s to 100 m/s and it compares the turbulent and laminar flows of the fluid using Reynolds number. Velocity (m/s) Length (m) Kinematic Viscosity Reynolds Number Type Of Flow 0.001 1 0.00001513 66.

09385327 66 < 2300 Laminar flow 0.005 1 0.00001513 330.4692664 330 < 2300 Laminar flow 0.01 1 0.00001513 660.9385327 661 < 2300 Laminar flow 0.035 1 0.00001513 2313.284865 2300 < 2313 > 4000 Transition flow 0.05 1 0.00001513 3304.692664 2300 < 3305 > 4000 Transition flow 0.1 1 0.00001513 6609.385327 6609 > 4000 Turbulent flow 0.5 1 0.00001513 33046.92664 33047 > 4000 Turbulent flow 1 1 0.00001513 66093.85327 66094 > 4000 Turbulent flow 5 1 0.00001513 330469.2664 330469 > 4000 Turbulent flow 10 1 0.

00001513 660938.5327 660939 > 4000 Turbulent flow 50 1 0.00001513 3304692.664 3304693 > 4000 Turbulent flow 100 1 0.00001513 6609385.327 6609385 > 4000 Turbulent flow Table 1: inlet velocities comparison Laminar model Figure 1: Pressure distribution at Velocity of 0.001 m/s The figure above shows the fluid flow tube in which it enters from the bottom of the tube at a constant pressure and the inlet velocity at which the fluid enters the tube is 0.001 m/s. As the fluid approaches the tube curvature, low-pressure builds up at the inside part at this section indicated by blue region of the scale and as a result, there is an increase in air velocity at this region.

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