Questions tagged [mechanical-engineering]

Questions within the problem domain of mechanical engineering. Mechanical Engineering can be a broad field; consider choosing more specific tags if they apply.

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2 answers
59 views

Pumping machine (Centrifugal ) fails to pump

I have a centrifugal pumping machine that fails to pump up consistently. When powdered on, it spills up water, then stops and continues intermittently like that without a consistent flow of water out. ...
1 vote
1 answer
394 views

Calculating mass flow rate of a scramjet engine?

First post here. I'm an undergraduate ME interested in fluid mechanics. I came across scramjets and I was interested about the engine. I want to calculate the mass flow rate of the engine and I made ...
0 votes
0 answers
37 views

How to make Peaucellier–Lipkin linkage work?

I tried in math.stackexchange.com and they send me here. First: Don't crucify me for not "doing math", or asking a dumb question. School was a long time ago, and lose what you don't use. My ...
0 votes
3 answers
297 views

Can a compressor give the same discharge pressure even if suction pressure varies?

The task is to maintain compressor discharge pressure at 200 bars. The inlet pressure varies with time from 200 bars to 10 bars (emptying a compressed air tank and compressing to transfer it to ...
0 votes
1 answer
57 views

Did anyone ever make training wheels for the original Segway personal transporter device?

I am curious to know if Segway, or any other company, has ever made front and rear training wheels for the original version of the Segway personal transporter device. To help illustrate what I mean by ...
-1 votes
2 answers
186 views

How to attach a metal rod to an air cylinder?

I have signed up for an engineering class, and the first project is purely mechanical. I've never done mechanical work, so this is quite interesting to me. I have come up with the following project - ...
0 votes
2 answers
585 views

How can a non flowing fluid have kinetic energy?

I am currently studying engineering thermodynamics from Cengel and Boles and there it is given that total energy of non flowing fluid per unit mass basis is given as $e=u+\frac{v^2}{2}+gz$.But if the ...
0 votes
2 answers
144 views

Net force exerted by spring

I want to find the exact net force exerted by the spring between pt. P and C, when it is compressed till point P with some mass, m attached to it and released (assuming spring goes to pt. C after its ...
1 vote
1 answer
109 views

Static discharge inside a fuel tank

I am trying to build a sort of paramotor powered by hydrogen, my rough design looks like this; First dilute sulfuric acid is electrolyzed in a sealed aluminium container. Second, the valve is ...
0 votes
1 answer
47 views

What is the name for a design element which includes trusses within a member?

I cannot think of what to call this design technique, where a truss-like structure is used within a member to provide strength and rigidity with minimized weight. I’ve included a picture which ...
1 vote
2 answers
318 views

Clock pendulum period vs driving weight

I've got a weight-driven pendulum clock, I increased the driving weight by 10% and the period decreased by 1%. Why? What's the equation? The pendulum is length = 32cm; bob weight = 7g; rod weight = 7g....
2 votes
2 answers
72 views

How to work out the kWh required to compress hydrogen gas?

I am trying to work out the kWh/kg of compression of hydrogen. I have used the isentropic compression calculations and get values for the entropy but am unsure how to get this to a kWh value. I might ...
0 votes
1 answer
40 views

Question about scaled models of compressors and turbines

Hello I am an engineering student and I have some questions about scaled models for compressors and turbines: When building scaled models of compressors or turbines to analysis them, what ...
1 vote
0 answers
48 views

How to calculate the torque disturbance of an unbalanced flywheel?

I would like to understand how an unbalance of a flywheel affects the dynamics of a simplified mechanical model. Assuming that the mechaincal dynamics can be modeled as (neclecting inertia of the ...
0 votes
1 answer
26 views

Searching for geometric modeller to investigate behaviour of beam when deflected

I have the scenario where I wish to model the movement of a simply supported beam under a central point load. I've done some stuff in R Studio to come up with deflection plots and that's fine. In ...
0 votes
1 answer
136 views

Making a three phase squirrel cage induction motor in PLECS?

I was just curious if I was to make a Three phase squirrel cage induction motor connected to a mechanical load System Block Diagram in PLECS with a rated frequency of 60hz, 6 poles, 220V rated stator ...
1 vote
1 answer
3k views

Tolerances in a pin-hole assembly

Hi guys, can someone explain how to do this question? This question is under Geometric Dimensioning and Tolerances and I am clueless on how to tackle problem like this. EDIT This is the explanation ...
2 votes
1 answer
110 views

How do you calculate the chain tension required when compressing bulk material over a conveyor?

Bulk material is conveyed over a slat conveyor, and the material is leveled with overhead rollers while being transported in the conveyor to maintain an even material height. Most of these "levelers" ...
1 vote
1 answer
112 views

Are there is vanadium-free high speed steels?

Vanadium is present in all high speed steel grades. Unfortunately vanadium is not only very expensive but is also a well known cytotoxic metal. Some workers get a severe persistent cough lasting for ...
0 votes
2 answers
53 views

Activate a mechanical end-stop with a lever

I would like to be able to record the motion of the shafts on a loom. I have some mechanical end-stops, and would like to trigger them with levers that raise and lower when the treadles at the base of ...
0 votes
1 answer
2k views

Calculate the required torque of a motor

I want to know how much torque I need for my engine. Imagine a wheel with a motor in the center. One like this: Let's say the wheel measures 400mm, weighs 10KG, what is the formula to make that ...
2 votes
2 answers
108 views

Passive mechanical element that can act as counterforce for a spring

An elavator is a moving cabin that gravity acts on. On the scales of the typical elevator application (a skyscraper for example), gravity is constant. So the gravitational force can be counteracted by ...
0 votes
1 answer
29 views

DLC wear resistance

I read that a thickness of one micrometer of DLC coating (which, if I understood correctly, shows similar properties to diamond), increases the lifespan of an item plated with it from a week to more ...
1 vote
1 answer
84 views

Are there any advantages of using BEM for contact problem over FEM, apart from lesser computational cost?

FEM - Finite Element Method BEM - Boundary Element Method If we had access to "enough" computational resources (to discretize the entire volume domain in FEM to the same degree of fineness, ...
0 votes
0 answers
16 views

I have a question about INISTATE Code (Analyzing a curved plate)

I'm studying welding-induced residual stresses for curved steel plates. So, I need to use the INISTATE code taking initial stresses. This is the picture that I want to analyze. I divided a curved ...
1 vote
2 answers
197 views

What is the type of hinge used in fold-down car tv's?

I am trying to find out what type of hinge or mechanism is used in fold down car TV's. I need to buy one for a project I'm working on but dont know the name. See picture above.
3 votes
4 answers
169 views

The behavior of the stress-strain curve of metal, containing a void

Let's assume that in a metal sample without any dislocation, there is a void. Then we conduct a uniaxial tensile test.
-1 votes
1 answer
231 views

Need help with converting rotary to linear reciprocating

First of all, not an engineer. Clueless to proper lingo or terminology. Project. Looking to create a compact, pen like device by using a 12v dc motor to create a reciprocating motion. Kind of similar ...
0 votes
2 answers
194 views

How to calculate traction force w.r.t. rotational speed of a shaft mounted at a certain angle on a surface?

I am designing a new mobile robot platform and i need a generic solution for the robot in order to establish a proper mathematical modeling. My question is about calculation of the traction force of ...
0 votes
0 answers
12 views

High temperature in seal oil vacuum pump (not in the bearing), steam power plant. Why the seal oil vacuum pump suddenly increased in temperature?

Seal oil vacuum pump in steam power plant, suddenly have temperature increased, it's in the pump's body, not in the bearing. Why is that happen? I noticed that temperature of main seal oil tank in ...
1 vote
2 answers
62 views

Ideas for running 2 gas engines to 1 shaft with pulleys

First time posting, but love the forum. Hopefully this hasn't been asked before. I could only find the question in relation to electric, not gas engines. I own a pressure washing business, and my ...
0 votes
1 answer
92 views

Estimating yaw torque and power of HAWTs

I am trying to estimate the amount of torque and power required to rotate a 3 bladed Horizontal Axis Wind Turbine (HAWT) about a vertical axis("yaw" motion). I would like to estimate the ...
0 votes
0 answers
13 views

What does the resonance frequency mean in inertia matching

Like Kollmorgen shows in this PDF how you can calculate the resonance frequency of a motor coupled to a load. But with what can I Compare this frequency? It is clear that a higher resonance frequency ...
-1 votes
0 answers
44 views

Could a miniaturised, lightweight Direct Air Capture (DAC) capability for CO2 be incorporated into industrial air conditioning units?

Rather than focus on the daunting task of upscaling demonstration plants on the lines of Climeworks to the extent necessary to remove the gigatonnes of CO2 scientists deem necessary should we not ...
0 votes
2 answers
219 views

Is it possible to seal a perfectly smooth surface?

I've heard that a surface roughness needs to be within a defined range, but in theory, is it possible to seal a perfectly smooth surface? E.g. with an o-ring, static or dynamic? Intuition tells me ...
0 votes
1 answer
196 views

What is the name of this piece in the image attached?

What is the shiny metal piece around the tube in the picture called?
2 votes
1 answer
126 views

How to compute the size of a polygon moving along non-circular guide rails

I am trying to compute the optimal (a non-optimal solution would also work) size of carts that can move along guiding rails. Each cart is connected to the rails at two points. Each cart is also ...
0 votes
1 answer
23 views

Nuclear pulsejet

As the title suggests, I am wondering about the feasibility of Nuclear powered pulsejet engines, including Radioisotope Thermoelectric Generators (RTGs). I am not talking about Nuclear pulse rockets, ...
0 votes
1 answer
277 views

Push / Pull Steering on an axle

I have a base with 4 wheels, the rear axle is a motor which drives the base forward or backwards, this contains a diff, so there's no problem there. The front axle is a steering axle like that in a ...
1 vote
2 answers
188 views

Reacting Propeller Torque?

A motor is used to drive a shaft that is geared through 1:1 bevel gears to a propeller. The shafts are mounted on bearings in a hard casing that is attached to a 2nd ground. I want to know if the 2nd ...
1 vote
0 answers
19 views

-AN Fitting Compatibility

I have a -6 AN fitting on the end of a hose. I am not familiar with AN fittings and I don't understand how to interpret the table at the bottom of the Wikipedia page on this subject. Does this table ...
3 votes
2 answers
311 views

Modeling rigid body dynamics: Trouble with equations, encountering nonsense answers

Hi, I am working on modeling a simple rigid body dynamic system through a certain range of motion. Here is the picture of the system. I am trying to solve the system for the variables $x_1'', y_1'', ...
6 votes
1 answer
235 views

What does a higher eject force do in a clutch?

I am looking at two clutches and the details on both are identical. The only difference is the eject force. One is 3300 and one is 3600. Does a higher eject force mean higher performance? And also ...
0 votes
1 answer
87 views

Can I drive a pulley with two shaded pole motors using one motor at a time with different size pulleys for speed control?

Using two same RPM shaded pole motors, one with a one inch diameter motor and one with a two inch diameter. Using a DTDP switch to swap power from one pulley to the other. For a two speed rotation ...
0 votes
1 answer
259 views

Drafting - Specifying multiple hole quantities

First post in this stack but curious on if there is a 'right' answer (within Australian or ISO standard) for how to quantify numerous holes of same size/properties on a drawing. In the past I've seen (...
0 votes
1 answer
186 views

What are rules of thumb for designing a gravity feed system for cylinders?

So, I just printed out this battery holder off Thingaverse. Unfortunately, it doesn't work very well, so I'm interested in redesigning it. There's a number of issues but the most annoying one is ...
1 vote
1 answer
765 views

Is there a formula that relates the two angles in a crank rocker?

I'm working on a mechanism that requires a crank rocker - is there a formula that relates the angle (to some fixed reference; horizontal, vertical, whatever) of the driving "crank" to the ...
0 votes
3 answers
96 views

Need help analyzing torque transfer and slippage condition between parts

I have a scenario where Plate A (light blue) shown in the image below is being pressed against two different plates that are in contact with different sections of Plate A. I would like to know which ...
0 votes
1 answer
472 views

Stress concentrations around rivets in compression

The stress concetration factor for an unfilled hole is around 3, but it decreases when a rivet is present. What factor can we expect for a hole with a rivet in it in compression?
1 vote
2 answers
459 views

What is reason of low axial velocity at tip and hub of an axial turbine?

I am analyzing results of my turbine simulation. I have created one line from hub to casing at downstream of the flow...please see the following figures. I want to investigate along this line how the ...

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