Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev
Mechanical Engineering SSC JE (Technical)
Mechanical Engineering : Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev
The document Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev is a part of the Mechanical Engineering Course Mechanical Engineering SSC JE (Technical).
All you need of Mechanical Engineering at this link: Mechanical Engineering
BOUNDARY LAYER THEORY
- The concept of boundary layer was first introduced by L. Prandt in 1904.
- Boundary layer is a region in the immediate vicinity of the boundary surface in which the velocity of flowing fluid increases gradually from zero at the boundary surface to the velocity of the main stream.
- Boundary Conditions of Boundary Layer Region
(i) at y = 0, v = 0
(ii) at y = d, v = V0 (d = boundary layer thickness V0 = free stream velocity)
(iii) at y = d,
= 0 [∵ Q v = V0 = constant]
(iv)
- Boundary layer thickness (d) It is defined as the distance from the boundary surface in which the velocity reaches the 99% of the velocity of the main stream.
y =d
for v = 0.99 V0 - Displacement Thickness (d*) It is the distance measured normal to the boundary, by which the free stream is displaced on account of the formation of boundary layer.
The quantity (V0 – v) is known as the velocity defect. - Momentum Thickness (q)
The ratio of displacement thickness to momentum thickness is called the shape factor (H)
- Its value should always greater than 1
- Energy Thickness
- Von-Korman momentum integral equation
- Blassius experimental results/ when
- Laminar Conditions : Velocity distribution is parabolic
(i) Boundary Layer thickness
(ii) Local coefficient of drag C*D
(iii) Avg. Coefficient CD
- Laminar Conditions : Velocity distribution is parabolic
- Turbulent Conditions : Velocity distributions is logarithmic
(i)
(ii)
(iii)
where
d = Boundary layer thickness
t = Shear stress at solid surface
x = Distance from where solid surface starts
- Boundary Layer Separation It is caused by adverse pressure gradient
- Location of Separation point : The separation point S is determined from the condition
For a given velocity it can be determined whether the B.L.(Boundary layer) has separated or on the verge of separation or will not separate from the following conditions :
1.
< 0 : Flow has separated.
2.
= 0 : Flow is on verge of separation.
3.
0 : Flow is attached with the surface
- Methods of Preventing Separation
(i) Rotating the boundary in the direction of flow.
(ii) Suction of the slow moving fluid by a suction slot.
(iii) Supplying additional energy from a blower.
(iv) Providing a bypass in the slotted wing.
(v) Providing guide blades in a bend.
(vi) Injecting fluid into boundary layer.
(vii)Streamlining of body shapes.
Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!
|
Author
|
Views
1.3K |
Rating
4.9
|
Description
Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev notes for Mechanical Engineering is made by best teachers who have written some of the best books of
Mechanical Engineering. It has gotten 1301 views and also has 4.9 rating. You can download Free Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev pdf from EduRev by
using search above. You can also find Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev ppt and other Mechanical Engineering slides as well. If you want Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev
Tests & Videos, you can search for the same too. Mechanical Engineering Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev Summary and Exercise are very important for
perfect preparation. You can see some Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev sample questions with examples at the bottom of this page. Complete
Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev chapter (including extra questions, long questions, short questions, mcq) can be found on EduRev, you can check
out Mechanical Engineering lecture & lessons summary in the same course for Mechanical Engineering Syllabus. EduRev is like a wikipedia
just for education and the Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev images and diagram are even better than Byjus! Do check out the sample questions
of Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev for Mechanical Engineering, the answers and examples explain the meaning of chapter in the best manner. This is
your solution of Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev search giving you solved answers for the same. To Study Chapter 9 Boundary Layer Theory - Fluid Mechanics, Mechanical Engineering Mechanical Engineering Notes | EduRev for Mechanical Engineering
this is your one stop solution.
83 docs|53 tests
Related Searches
Important questions
,Mechanical Engineering Mechanical Engineering Notes | EduRev
,practice quizzes
,Objective type Questions
,Semester Notes
,Previous Year Questions with Solutions
,mock tests for examination
,past year papers
,Summary
,shortcuts and tricks
,MCQs
,ppt
,video lectures
,Mechanical Engineering Mechanical Engineering Notes | EduRev
,Mechanical Engineering Mechanical Engineering Notes | EduRev
,Free
,Exam
,Chapter 9 Boundary Layer Theory - Fluid Mechanics
,Extra Questions
,Viva Questions
,study material
,Chapter 9 Boundary Layer Theory - Fluid Mechanics
,Chapter 9 Boundary Layer Theory - Fluid Mechanics
,Sample Paper
;
|
Follow Us
|