Mechanical Engineering Community

• ## Mechanical Engineering Knowledge

Welcome to Mechanical Engineering Community forum - The knowledge community connecting mechanical engineering professionals across the globe. The success of this community depends on your participation. Do not read just as a guest... Be an active member

• ### Fit_and_Dimensional_Tolerances

Fit_and_Dimensional_Tolerances_Mechanical_Engineering_Drawing Source Ashish K Darpe Department of Mechanical Engineering IIT Delhi Thanks to Mr. Ashish K Darpe Regards Saurabh Jain

saurabhjain
Powerpoint Presentations 7

### introduction to cfd Computational fluid dynamics

its useful ppt about CFD •Computational fluid dynamics (CFD) is the science of predicting fluid flow, heat transfer, mass transfer, chemical reactions, and related phenomena by solving the mathematical equations which govern these processes using a numerical process.

Powerpoint Presentations 5

### Machine Design II ppt

Presentation on Design of- Clutch Brake Belts Chain Gears

saurabhjain
Powerpoint Presentations 5

### Geometric Dimensioning and Tolerancing

Geometric Dimensioning and Tolerance ppt Five powerpoint presentations

saurabhjain
Powerpoint Presentations 7

### Metal Forming

Powerpoint Notes on Metal forming Topic includes— Hot &Cold working Forging Extrusion Rolling Drawing

saurabhjain
Powerpoint Presentations 5

### Automotive Technology, 5th Edition James D. Helderman ppts

A COMPLETE INSTRUCTOR AND STUDENT SUPPLEMENT PACKAGE - Continued These ppts are set of instructor and student supplements. . A FOCUS ON DIAGNOSIS AND PROBLEM SOLVING The  primary focus of these ppts is to satisfy the need for problem diagnosis. Time and again, the author has heard that technicians need more training in diagnostic procedures and skill development. To meet this need and to help illustrate how real problems are solved, diagnostic stories are included throughout. Each n

Robinson Kiprotich k
Powerpoint Presentations
• ### Explain in an orderly manner how the force in the member of a truss be detected using the method of joint.

Explain in an orderly manner how the force in the member of a truss be detected using the method of joint. 1. You can answer this question 2. You can like the best answer 3. You can share the question.

saurabhjain
Mechanical Engineering Questions

### What are the Advantages of using LPG in Car?

Is it good to use LPG in car ? what are the Advantages and Disadvantages of using LPG in Car? 1. You can answer this question 2. You can like the best answer 3. You can share the question...

saurabhjain
Mechanical Engineering Questions 2

### What is the role of nitrogen in welding?

Source: What is the role of nitrogen in welding?

saurabhjain
Mechanical Engineering Questions 3
• ### 18 Mechanical Properties Which Every Mechanical Engineer Should Know

Selection of material is an important aspect for manufacturing industries . The quality of product is highly depends upon its material properties. These properties are used to distinguish materials from each other. For Example: A harder material is used to make tools.A ductile material is used to draw wires. So the knowledge of mechanical properties of material is desirable for any mechanical student or for any person belongs to mechanical industries. This post brings top 18 mechanical propertie

saurabhjain
Material Science

### Types of Welding

Welding is a process of joining similar and dissimilar metals or other material by application of heat with or without application of pressure and addition of filler material. It is used as permanent fasteners. Welding is essential process of every manufacturing industries.  In fact, the future of any new metal may depend on how far it would lend itself to fabrication by welding. The weldability has been defined as the capacity of being welded into inseparable joints having specified pro

saurabhjain
Manufacturing Technology 1

### Difference between Hot Working and Cold Working

They both are the metal forming processes. When plastic deformation of metal is carried out at temperature above the recrystallization temperature the process, the process is known as hot working. If this deformation is done below the recrystallization temperature the process is known as cold working. There are many other differences between these processes which are described as below. Difference between Hot Working and Cold Working: S.No.

saurabhjain
Manufacturing Technology 4

### CLASSIFICATION OF FLUIDS

Ideal fluid: A fluid, which is incompressible and having no viscosity, is known as an ideal fluid. Ideal fluid is only an imaginary fluid as all the fluids, which exist, have some viscosity. Real fluid: A fluid, which possesses viscosity, is known as real fluid. All the fluids, in actual practice, are real fluids. Example : Water, Air etc. Newtonian fluid: A real fluid, in which shear stress in directly proportional to the rate of shear strain or velocity gradient,

saurabhjain
Fluid Mechanics 1
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3. ## Good indoor quality process

What actions taken during design and construction do you think make the difference between a building with good indoor air quality.
4. ## Thermal comfort, what's your priority?

As a building designer, what do you believe is the single MOST important thing you should remember about thermal comfort in terms of indoor temperature during the design process? and why?
5. ## Ethical question about thermal comfort

Is it ethical for a building designer to shift some of the burdens for thermal comfort to the occupants of a building—for example, by requiring adaptive responses from building users? Would your response to this question change from building type to building type?
6. ## Ethical question about thermal comfort

Is it ethical for a building designer to shift some of the burdens for thermal comfort to the occupants of a building—for example, by requiring adaptive responses from building users? Would your response to this question change from building type to building type?
7. ## Absorption Chiller

Hi! I had a question regarding absorption chillers: Why must the mixture of water and lithium bromide be cooled by the cooling tower in the Absorber? Is it correct to say that even though the lithium bromide spray attracts the water vapour, the water vapour remains in gaseous form and so the mixture must be cooled to achieve liquid state before entering the generator? If not, wouldn't any remaining heat in the mixture would reduce the amount of heat required from the hot water (source), therefore reducing the total energy consumption? Thank you in advance for the help! Best regards, George
8. ## Condensate liquid seal

A system is not allowed to operate at higher then 50mbar. A condensate drain is introduced into the system to remove excess liquid (assume water) and act as a seal for less then 50mbar, any higher and the seal should break and let the air escape. Operating between 0 and 50mbar the liquid will be pushed down the pipe, raise the liquid level in the pot and thus expel condensate, if 50mbar is reached then the fluid should be completely pushed down the pipe and the air allowed to bubble out. I have used bernoullis equation to determine that the hieght of the fluid in the pipe should be 0.51m for 0mbar, a force balance on the fluid element shows that the diameter of the pipe does play a role but when looking at pressures the diameter does not. Does this mean that for a pipe (for arguments sake) of 150mm diameter, we only need to ensure the height of the fluid at 0mbar is 0.511m and then as the pressure increases to 50mbar the air will indeed escape and keep the system from over pressurizing? fluid seal.pdf
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10. ## HAZOP & HAZIP

HAZOP, which stands for hazard and operability study, is used to identify abnormalities in the working environment and pinpoint the root causes of the abnormalities. It deals with comprehensive and complex workplace operations, which, if malfunctions were to occur, could lead to significant injury or loss of life. HAZID stands for hazard identification. It is more of a general risk analysis tool designed to alert management to threats and hazards as early in the process as possible. The classification is made on the basis of probability and consequences. A HAZID study provides a qualitative analysis of a work site in order to determine its worker safety risk level. Both HAZID and HAZOP are risk analysis tools used in the workplace
11. ## E board contactor

Hi all, May I know a contactor in E board (in an apartment) burn will cause damage of household product? Eg, computer, fan. Thanks you so much.
12. ## Shaheem Hussein

Looking for 75/6 BMW motorcycle wiring diagram

13. ## 99 chevy

my chevy keeps jumping gears
14. ## Calculating the required power for a Cast Iron Boiler :

A: To approximately calculate the required power for a climate such as Tehran’s, first multiply the useful area by 100 kcal and for each residential unit, add 6000 kcal to its product. For example, if we have a building with 2600 square meters of useful area and 18 residential units, the required heating power would be: (100 x 2500) + (18 x 6000) = 358,000 kcal Add 20% to the above calculation as the safety margin. B: According to the area, unit numbers, use of your building, and possible pools, etc., you can consult the technicians of Damatajhiz Company. Damatajhiz website delivers the technical specifications and prices for many models of cast iron hot water boilers from credible brands and with original guarantee to give you the joy of a good purchase.

17. ## Pendulum Hammer Impact Force Calculation

Gabe, that's just standard US Government quality service (I'm really quite familiar with it all; I used to work for the US Navy as a civilian). DrD
18. ## Pendulum Hammer Impact Force Calculation

The document quality is pretty horrendous 😂
19. ## Head of technical support

This is a blog? It looks like a job ad to me. DrD
20. ## Pendulum Hammer Impact Force Calculation

Looks like you now have enough reading material to keep you busy for quite a while! I notice that, as usual, the quality of the document from DTIC is dismal; they must have the worst Xerox machines in captivity. DrD
21. ## Pendulum Hammer Impact Force Calculation

For future reference for anyone that comes across this post or is interested in more information. I came across this paper from 1972 by EW Clements: https://apps.dtic.mil/dtic/tr/fulltext/u2/746444.pdf "Shipboard Shock and Navy Devices for its Simulation", which goes into detail and actually measures impact velocities, peak anvil acceleration, and other relevant information.
22. ## Pendulum Hammer Impact Force Calculation

I guess I really didn't search hard enough. Thanks for finding this! I noticed in the paper that it refers to it as MIL-DTL-901D and I was looking for 901e. The difference being that the 901e is the most recent updated version, I didn't think to look for 901d. Again, thanks for the help, it's very much appreciated. This definitely will help me.
23. ## Fit_and_Dimensional_Tolerances

I find this really useful. A nice refresher presentation.
24. ## Equation for the spring constant of an orthotropic, rectangular wire spring

I hope I can get some help with this problem as I've been struggling with it for a long time. I have a helical tension spring with radius R and a square wire cross section and made of orthotropic material. I'm trying to derive an equation for the spring constant k by equating the energy stored by the spring 1/2 k x^2, where x is the distance stretched, with the energy stored U_t by a shaft under torsion of equivalent length so 1/2 k x^2=U_t As explained in the title, I have a particular situation because the material is orthotropic and the cross-section of the shaft is a rectangle as shown in the attached image. I already have an expression for the torsional rigidity GJ of an orthotropic rectangular shaft with shear moduli G_{zx} and G_{zy}: GJ=a b^3 G_{zx} [&beta;] where [&beta;] is a series where you sum from n=1,3,5... to infinity. When I equate 1/2 k x^2=U_t=(GJ/2L) [&theta;]^2 I can plug in [&theta;]=x/R (the angle the shaft has been twisted by is roughly equal to the angle each coil of the spring gets stretched by) so k=GJ/(L R^2) where L=2[&pi;] R N_a and N_a are the number of active coils in the spring. To me the equation looks complete but the problem is that when I enter values like a=0.005m, b=0.0025m, G_{zx}=1159.1MPa, G_{zy}=974.3MPa, N_a=5, and R=0.01m I get k=632.642 instead of k=2780, which is the right answer. Since I have that the torque on the shaft is T=a b^3 G_{zx} [&theta;] [&beta;] I tried other equations for U_t where U_t=(1/2) T [&theta;] or U_t=(T^2 L)/2GJ but none of the answers come even close, 198.75 and 62.4393. Am I doing something wrong when equating the two energies?
25. ## Pendulum Hammer Impact Force Calculation

Gabe, I found the attached article on the 'net. I have not read it through, but I'll bet it has some information for you. The internet also has tons of other information on this machine. DrD MediamWeightShockMachine.pdf
26. ## Pendulum Hammer Impact Force Calculation

Ah, Gabe! I knew I had seen that figure before, but I certainly did not remember the mil-spec designation! Sadly, really nothing is conserved all the way through the motion. Energy is conserved before the impact and after the impact, but energy is not conserved during the impact. This is where the coefficient of restitution stuff comes in. I would strongly suggest that you keep looking for more definition from the military. There has to be a more complete description, because without such, you cannot possibly have a standard test. If everybody has a different test machine, there is nothing standardized or comparable about the results. DrD
27. ## Pendulum Hammer Impact Force Calculation

Picture of test machine for reference
28. ## Pendulum Hammer Impact Force Calculation

This particular test is MIL-DTL-901e. The information given within the standard is essentially what I have provided. No detailed drawings of the shock machine showing complete dimensions, no information on materials of the hammer/anvil, no spring coefficients, really no information to allow you to fully model this test. That is why I will settle for ballpark numbers. But I appreciate you taking the time to try to assist me in this problem. I will take a look at the link you suggested and see if I can produce some numbers. I appreciate your response. It definitely would be useful if there were some available values in the spec and if I had access to a machine to use an accelerator to get readings would be ideal, but I don't have access to one.
• ### Who's Online   1 Member, 0 Anonymous, 74 Guests(See full list)

• Looking for 75/6 BMW motorcycle wiring diagram
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• A leading well-known multinational company in the oil and gas field is seeking to hire in Egypt
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Write (Mechanical Rotating Equipment Specialist) in the subject line or it will be neglected

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• ### Posts

• What actions taken during design and construction do you think make the difference between a building with good indoor air quality.
• As a building designer, what do you believe is the single MOST important thing you should remember about thermal comfort in terms of indoor temperature during the design process?  and why?
• Is it ethical for a building designer to shift some of the burdens for thermal comfort to the occupants of a building—for example, by requiring adaptive responses from building users? Would your response to this question change from building type to building type?
• Is it ethical for a building designer to shift some of the burdens for thermal comfort to the occupants of a building—for example, by requiring adaptive responses from building users? Would your response to this question change from building type to building type?
• Hi! I had a question regarding absorption chillers: Why must the mixture of water and lithium bromide be cooled by the cooling tower in the Absorber? Is it correct to say that even though the lithium bromide spray attracts the water vapour, the water vapour remains in gaseous form and so the mixture must be cooled to achieve liquid state before entering the generator? If not, wouldn't any remaining heat in the mixture would reduce the amount of heat required from the hot water (source), therefore reducing the total energy consumption?   Thank you in advance for the help!   Best regards,   George

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