Flow Around a Bend in a Rectangular Duct Partial Report
docx
keyboard_arrow_up
School
University of Illinois, Urbana Champaign *
*We aren’t endorsed by this school
Course
335
Subject
Mechanical Engineering
Date
Apr 3, 2024
Type
docx
Pages
4
Uploaded by AdmiralHamster1144
Flow Around a Bend in a Rectangular Duct Partial Report Krishna Ramasubramanian pr16@illinois.edu
9/26/2022
The primary objective of this lab is to measure resultant force on air by a curved duct, determining if control volume analysis based on the linear momentum principle is valid. We’re also trying to analyze if the tangential velocity of air around the bend can be modeled with an idealization – the free-vortex model. Modeling and understanding this type of airflow is very influential in the design and shape/material optimization of fluid flow across any curved and contained chamber.
We’re first trying to measure resultant force caused by the curvature of the duct onto the air moving inside it. This requires a curved duct and a controllable air flow going through the duct. In addition, our apparatus must require a multitude of pressure transducers along the path of the travelled air to assess fluid pressure at various points of the duct. Once this setup is created, we can then use the principle of conservation of momentum and control volume to deduce the amount of force is exerted on the air because of the duct. The pressures only are exerted from inside the walls of the duct, which we can then take as 𝑭
= − ∫ 𝑝𝒏
dA as the sum of all the pressures across the inside walls’ area. Looking at control volume analysis, force can be derived as a function of linear momentum. This analysis breaks it down to 2 dimensions, making it such that there is no result of force as a result of the spanwise direction, modeled as ∑ 𝑭
ext = ∫ 𝒖
𝜌
(
𝒖
∙ 𝒏
)d
𝐴
. Lastly, using the free-vortex model, we can examine the flow of the fluid as a function of the radial distance to the center of rotation. With the theories out of the way, we can examine the results of the data that we collected with the apparatus. The forces in Appendix A tend to have Fx to be greater than Fy, and the flow rates correspond with the forces directly. The trend is consistently lower Fy than Fx for all the flow rates, and it shows that the higher the flow rate, the greater the forces are as well.
The assumption of a free vortex model (FVM) is valid until the point of deviation from the model which occurs at 75-80 mm consistently. This, however, is a very small deviation that can be explained away by slight physical discrepancies and errors in measurement. The rigid body model results in Cp creating the inverse graph of the FVM. This is the exact opposite of what is also seen at the experimental data. As a result, there is no correlation to the rigid body model, invalidating it as a means to model the physical results.
Next, the constant velocity model results in a constant pressure. The experimental pressure varies significantly as a function of the radius and does not remain constant. Therefore, this model is invalidated as well.
In conclusion, the forces inside the duct are modeled by momentum conservation and control volume analysis. Taking the integral and using the control volume both yield the same results. The flow rate also determines the amount of force that the duct exerts on the air. Lastly, we see that the FVM is the best representation of the flow pressure. The other models do not correlate to the physical data, and therefore are not a means to model the physical results.
1
2
0
5
10
15
20
25
Integration Forces
Fx = 1 Fy = 2
F (N)
Appendix A
Appendix B
Appendix C
50
55
60
65
70
75
80
85
90
95
100
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
Coefficient of Pressure vs. Radius
Experimen-
tal Data
Free Vortex Model
Radius (mm)
Coefficient of Pressure, Cp
50
55
60
65
70
75
80
85
90
95
100
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
Coefficient of Pressure vs. Radius
Experimen-
tal Data
Radius (mm)
Coefficient of Pressure, Cp
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
Appendix D
50
55
60
65
70
75
80
85
90
95
100
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
Coefficient of Pressure vs. Radius
Experimen-
tal Data
Radius (mm)
Coefficient of Pressure, Cp
Related Documents
Related Questions
Fluid Mechanics Problem:
Assume all fluids are 20oC.
arrow_forward
Problem 4: The power P developed by a wind turbine is a function of diameter D,
air density p, wind speed V, and rotational rate @. Viscous effect is negligible.
(4a) Rewrite the above relationship in a dimensionless form;
(4b) In a wind tunnel, a small model with a diameter of 90cm, rotating at 1200 RPM
(revolution per minute), delivered 200 watts when the wind speed is 12m/s. The
data are to be used for a prototype of diameter of 50m and wind speed of 8 m/s.
For dynamic similarity, what will be (i) the rotational speed of the prototype turbine?
(ii) the power delivered by the prototype turbine? Assume air has sea-level density.
arrow_forward
>
| E9
docs.google.com/form
تبديل الحساب
Questions
7 نقاط
Q1/ The power of 6-blade flat blade turbine agitator in a tank is a function of diameter of impeller, number of
rotations of the impeller per unit time, viscosity and density of liquid. From a dimensional analysis, obtain a
relation between the power and the four variables.
3.
صفحة 2 من
arrow_forward
PLEASE BOX YOUR ANSWERS
Problem 2
In an experiment conducted in a laboratory, the surface tension (Y)
acting on a rotating square plate in a viscous fluid is a function of the external torque (t),
plate length (a), area moment of inertia of plate (I), specific weight of the fluid (Y) and
angular displacement of the plate (0). Using Buckingham-Pi theorem, find a suitable set of pi
terms (in M, L and T primary dimensions). Your final answer should be written in proper
functional form. Refer Table 5.1/ page-296 for secondary dimension of the variables.
arrow_forward
Need help on both parts please
arrow_forward
You are employed as a mechanical engineer within an unnamed research center, specializing in the development
of innovative air conditioning systems. Your division is tasked with providing computer-based modeling and
design solutions using computational fluid dynamics through ANSYS software. Your primary responsibilities
involve the analysis of horizontal channel dynamics to meet specific criteria. Under the guidance of your
immediate supervisor, you have been assigned unique responsibilities within an ongoing project. As a member of
the research team, your role includes constructing an appropriate model and executing a sequence of simulation
iterations to explore and enhance channel performance. Figure 1 provides a visualization of the horizontal channel
under consideration. Consider 2D, incompressible, steady flow in a horizontal channel at a Reynolds number of
150. The schematic below illustrates the channel flow, not drawn to scale. For simplicity, neglect gravity. The
channel's…
arrow_forward
[1] Consider steady flow of air through the diffuser portion of a wind tunnel. Along the
centerline of the diffuser, the air speed decreases from uentrance to ut as sketched.
Measurements reveal that the centerline air speed decreases parabolically through the
diffuser. Write an equation for centerline speed u(x), based on the parameters given here,
Dee
x=0 to x=L.
arrow_forward
Fluid Mechanics Problem
arrow_forward
Hi, Please help me with this question and please show the full solution. Thank you very much
arrow_forward
The thrust F of a Free propeller, either aircraft of marine, depends upon density ρ, the rotation rate n in r/s, the diameter D, and the forward velocity V. Viscous effects are slight and neglected here. Tests of a 25-cm-diameter model aircraft propeller, in a sea-level wind tunnel, yield the following thrust data at a velocity of 20 m/s :
Rotation Rate, r/min____4800____6000____8000
Measured thrust, N____6.1____19____47
Use the dimensionless data to predict the thrust, in Newtons, of a similar 1.6-m-diameter prototype propeller when rotating at 3800 r/min and flying at 225 mi/h at 4000-m standard altitude.
arrow_forward
The power input P to a centrifugal pump is assumed to be a function of the volume flow Q, impeller diameter D, rotational rate Ohm, the density rho, and viscosity mu of the fluid. Rewrite this as a dimensionless relationship
arrow_forward
A jet engine on a test stand directs a stream of hot exhaust gasses against a vemcal wall. All of the exhaust gas leaving the wall after impact is in the y-z plane (ie no "x" direction velocity). The mass rate is 200 kg/s and the velocity is 400 m/s. (Note that the density and viscosity are not relevant) What is the force on the wall (include direction)?
arrow_forward
3
arrow_forward
A water pump increases the pressure of the water passing through it. The flow is assumed to be incompressible. For each of the three cases listed below, how does average water speed change across the pump? In particular, is Vout less than, equal to, or greater than Vin? Show your equations, and explain. (a) Outlet diameter is less than inlet diameter (Dout < Din) (b) Outlet and inlet diameters are equal (Dout = Din) (c) Outlet diameter is greater than inlet diameter (Dout > Din)
arrow_forward
(b) A wind-tunnel experiment is performed on a small 1:5 linear-scale model of a car, in order
to assess the drag force F on a new full-size car design. A dimensionless "drag coefficient"
Ca is defined by
C, =-
pu'A
where A is the maximum cross-sectional area of the car in the flow. With the model car, a
force of 3 N was recorded at a flow velocity u of 6 m s. Assuming that flow conditions
are comparable (i.e., at the same Reynolds number), calculate the expected drag force for
the full-sized car when the flow velocity past it is 31 m s (equivalent to 70 miles per
hour). [The density of air p= 1.2 kg m.]
arrow_forward
EXAMPLE Leaking Tank. Outflow of Water Through a Hole (Torricelli's Law)
This is another prototype engineering problem that leads to an ODE. It concerns the outflow of water from a
cylindrical tank with a hole at the bottom. You are asked to find the height of the water in the tank at any time
if the tank has diameter 2 m, the hole has diameter 1 cm, and the initial height of the water when the hole is
opened is 2.25 m. When will the tank be empty?
2.20 M
Water level
asime
Outiine
walls
200
200
30t
.00-
50-
D
10000
30000
tebe Revelion
50000
arrow_forward
can you please do all of them. thank you
arrow_forward
Particles in liquids achieve terminal speed very quickly. One can measure the time it takes for a
particle to fall a certain distance and then calculate the constant B. Suppose a steel ball bearing
(mass=0.86 grams) is dropped in a container of motor oil. It takes 12 s to fall 0.60 m.
(a) Estimate the terminal speed, Viem, assuming the ball bearing reaches terminal speed almost
immediately. (answer: Vterm 0.050 m/s)
(b) Calculate B. (answer: 0.17 kg/s)
(e) What is the speed of the ball bearing 11 ms after it is dropped? (answer: 0.044 m/s)
arrow_forward
A paramecium is an elongated unicellular organism with approximately 50 μmin diameters and 150 μmin lengths. It swims through water by whip-like movements of cilia, small hairs on the outside of its body. Because it moves "head first" through the water, drag is determined primarily by its diameter and only secondarily by its length, so it's reasonable to model the paramecium as a 70-μm diameter sphere. A paramecium uses 2.0 PW of locomotive power to propel itself through 20∘C water, where 1 pW = 1 picowatt = 10−12W.
What is its swimming speed in μm/s?
Express your answer in micrometers per second.
arrow_forward
2
arrow_forward
As we learned, Bernoulli's equation is not to be used in many situations. Let's say you are examining changes between two points in a flow.
Which ONE of these scenarios could you appropriately use Bernoulli's equation on?
O A turbine is situated between the two points
There are large changes in kinetic energy between the two points
The mass flow rate between the two points changes with time
There are large changes in density between the two points
There are large viscous losses between the two points
QUESTION 10
A 12 cm diameter jet of air strikes a plate positioned normal to the flow, with all air deflected away parallel to the plate. If the air flows at a
speed of 20 m/s, what is the force needed to held the plate in place? Do not use a linear momentum correction factor.
O 0.272 N
10.9 N
4510 N
5.45 N
0.340 N
arrow_forward
SEE MORE QUESTIONS
Recommended textbooks for you

Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press

Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON

Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education

Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY

Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning

Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
Related Questions
- Fluid Mechanics Problem: Assume all fluids are 20oC.arrow_forwardProblem 4: The power P developed by a wind turbine is a function of diameter D, air density p, wind speed V, and rotational rate @. Viscous effect is negligible. (4a) Rewrite the above relationship in a dimensionless form; (4b) In a wind tunnel, a small model with a diameter of 90cm, rotating at 1200 RPM (revolution per minute), delivered 200 watts when the wind speed is 12m/s. The data are to be used for a prototype of diameter of 50m and wind speed of 8 m/s. For dynamic similarity, what will be (i) the rotational speed of the prototype turbine? (ii) the power delivered by the prototype turbine? Assume air has sea-level density.arrow_forward> | E9 docs.google.com/form تبديل الحساب Questions 7 نقاط Q1/ The power of 6-blade flat blade turbine agitator in a tank is a function of diameter of impeller, number of rotations of the impeller per unit time, viscosity and density of liquid. From a dimensional analysis, obtain a relation between the power and the four variables. 3. صفحة 2 منarrow_forward
- PLEASE BOX YOUR ANSWERS Problem 2 In an experiment conducted in a laboratory, the surface tension (Y) acting on a rotating square plate in a viscous fluid is a function of the external torque (t), plate length (a), area moment of inertia of plate (I), specific weight of the fluid (Y) and angular displacement of the plate (0). Using Buckingham-Pi theorem, find a suitable set of pi terms (in M, L and T primary dimensions). Your final answer should be written in proper functional form. Refer Table 5.1/ page-296 for secondary dimension of the variables.arrow_forwardNeed help on both parts pleasearrow_forwardYou are employed as a mechanical engineer within an unnamed research center, specializing in the development of innovative air conditioning systems. Your division is tasked with providing computer-based modeling and design solutions using computational fluid dynamics through ANSYS software. Your primary responsibilities involve the analysis of horizontal channel dynamics to meet specific criteria. Under the guidance of your immediate supervisor, you have been assigned unique responsibilities within an ongoing project. As a member of the research team, your role includes constructing an appropriate model and executing a sequence of simulation iterations to explore and enhance channel performance. Figure 1 provides a visualization of the horizontal channel under consideration. Consider 2D, incompressible, steady flow in a horizontal channel at a Reynolds number of 150. The schematic below illustrates the channel flow, not drawn to scale. For simplicity, neglect gravity. The channel's…arrow_forward
- [1] Consider steady flow of air through the diffuser portion of a wind tunnel. Along the centerline of the diffuser, the air speed decreases from uentrance to ut as sketched. Measurements reveal that the centerline air speed decreases parabolically through the diffuser. Write an equation for centerline speed u(x), based on the parameters given here, Dee x=0 to x=L.arrow_forwardFluid Mechanics Problemarrow_forwardHi, Please help me with this question and please show the full solution. Thank you very mucharrow_forward
- The thrust F of a Free propeller, either aircraft of marine, depends upon density ρ, the rotation rate n in r/s, the diameter D, and the forward velocity V. Viscous effects are slight and neglected here. Tests of a 25-cm-diameter model aircraft propeller, in a sea-level wind tunnel, yield the following thrust data at a velocity of 20 m/s : Rotation Rate, r/min____4800____6000____8000 Measured thrust, N____6.1____19____47 Use the dimensionless data to predict the thrust, in Newtons, of a similar 1.6-m-diameter prototype propeller when rotating at 3800 r/min and flying at 225 mi/h at 4000-m standard altitude.arrow_forwardThe power input P to a centrifugal pump is assumed to be a function of the volume flow Q, impeller diameter D, rotational rate Ohm, the density rho, and viscosity mu of the fluid. Rewrite this as a dimensionless relationshiparrow_forwardA jet engine on a test stand directs a stream of hot exhaust gasses against a vemcal wall. All of the exhaust gas leaving the wall after impact is in the y-z plane (ie no "x" direction velocity). The mass rate is 200 kg/s and the velocity is 400 m/s. (Note that the density and viscosity are not relevant) What is the force on the wall (include direction)?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY

Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press

Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON

Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education

Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY

Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning

Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY