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3answers
163 views

How to accurately measure mass flow through server vents using an anemometer

I have to work out the air mass flow coming out each vent on a server and have proposed to use a hot wire anemometer to measure the air velocity at each vent by placing it slightly inside one outlets ...
1
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2answers
935 views

Driving many parallel shafts from one motor

Is there a preferred solution to the problem of driving parallel rotary shafts from a single motor? I have six shafts that I want to drive from one motor. The shafts are all: rotating the same ...
1
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1answer
326 views

How to calculate scarf ratio or lap overlap for composites?

I'm building a plane, and one of the solutions I've thought of for connecting the wing spars to the fuselage involves connecting carbon fiber parts. As mentioned in this answer, I found this ...
1
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1answer
1k views

How do I calculate the temperature change inside a box with a heat source? What if I ventilate the box?

I have a box (as shown below). I know the temperature outside of the box (for example you could use 293K) and I would assume the temperature inside the box is initially the same as outside of the box. ...
1
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1answer
156 views

Looking for a formula that states the stiffness of a composite [closed]

I am looking for a formula that states the breaking point of a composite - How much pressure it can withstand before it 'snaps'. Specifically I am looking for a formula that states the materials ...
1
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0answers
208 views

How to calculate monosymmetry index of an unequal angle? [closed]

I saw some formula involving integration. Is there a straightforward formula to calculate this instead given b, d, t and alpha angle between x-x and u-u axis?
1
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1answer
248 views

Shear Stress Formula

Could anyone tell me what the variables in this formula are? $$\tau=\frac{S\;a\; \bar{v}}{I\; t}$$ I believe it is used for shear stress and that $I$ is moment of inertia but unsure on the other ...
1
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1answer
137 views

How to determine heat exchanger equation?

What is the equation to determine the inside surface temperature along the length of the counter flow heat exchanger?
1
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1answer
1k views

Conjugate beam (M/EI)

I dont understand how the diagram of M/EI of conjugate beam drawn , can someone explain about it ? According to conjugate beam theorem , i know that the M/EI represent the w(x) , which is force per ...
1
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1answer
81 views

qualitative influence line of pinned support

For the highlighted part , why we need to replace the support at A with a roller guide ? We could see at A , it's a pinned support , right ? Pinned support will resist horizontal and vertical ...
1
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1answer
1k views

How to calculate deflection of a cantilever beam subject to point loading

I am trying to solve the following beam deflection problem: The cantilever beam is subjected to the point load at C. Generate the equation for the elastic curve by using the double ...
1
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1answer
63 views

How can I build a electronically controlled valve for a 1/4 inch tube

I'm looking for a practical efficient way to open and close a 1/4 inch gravity fed hose. Initially I was thinking of using a Solenoid, but can't find anything suitable. My second thought was using a ...
1
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2answers
305 views

Is continuous beam design deemed “unsafe” by any code of practice/design practice for reinforced concrete building structures?

I am asking this because some of my engineer friends said that they won't want to analyze beam as continuous beam for RC building structures, because it is "unsafe" to do so, whether it has anything ...
1
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2answers
762 views

Does the turbo-compressor increase the efficiency of car engine?

Once the turbo is on, more air can participate to the combustion, which also requires more fuel. Then, it's clear that the turbo can give more power (at the price of more consumption). Question 1: ...
1
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1answer
967 views

Pacejka Formula - natural values

For my racing game I am using a simplified Pacejka Magical Formula: $\mu_{lateral} = \mu_{0} * \mu_{1} * D * \sin(C * \arctan(B * x - E * (B * x - \arctan(B * x))))$ Where: $\mu_{lateral}$ is ...
1
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1answer
2k views

Sizing plate washers for through-bolting to concrete

We are working on some equipment that is going to be attached to existing, 3,000 psi reinforced concrete floor slabs. In some locations, the best way to do this is to through-bolt and 'sandwich' the ...
1
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3answers
1k views

How does Hysteresis in tires helps create friction?

I am currently reading “Fundamentals Of Vehicle Dynamics” by Thomas D. Gillespie. The author states how tires generate the required frictional forces for movement by 2 methods : 1)Hysteresis 2)...
1
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0answers
47 views

What changes can be made to a whistle to change these variables? [closed]

I have read that the longer the whistle the lower the pitch and the shorter the whistle the higher the pitch. But there are other factors. Pressure, size of the inlet, size of the outlet, diameter of ...
1
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2answers
591 views

What type of tires and wheels do I need to make a PVC beach cart?

I would like to make a beach cart that supports 200lbs and uses this design What type and dimension wheels and tires should I buy? I have a budget of $100.00 for the tires and wheels. I cannot ...
1
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0answers
103 views

Using a Copper Waterblock or Aluminum Heatsink to Cool Water via Thermo Electric Cooler [closed]

I am attempting to create a ThermoElectric Cooler to Chill Water. I have thought of two options as to how I can cool the water: Some limitations of the design: The water is still, not moving. No "...
1
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1answer
192 views

Easy model to calculate water flow rate over trough ledge?

Trough is 1.87 meters long and 0.5 meter wide and 0.22 meter deep. Water only flows over the 1.87 meter long side and from both sides (so x2). The water overflow is 0.012 meters tall (ruler ...
1
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2answers
138 views

Trying to shed some weight on my design, any thoughts?

I am trying to design a lifting mechanism and I would love some insight/opinions as to how I can shed some weight off it. The current weight I have for my mechanism is 187.5kg, however, this is ...
1
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1answer
226 views

Is triaxial carbon fiber gimmick?

Is there any benefit to using triaxial weave pattern instead of common twill?
1
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1answer
60 views

Up flow vs down flow through a porous fixed bed

How do I analyse for, or what do I need to consider, when comparing gravity-opposed vs gravity assisted flow in a tube containing a porous bed that partially shrinks (through partial mass loss) over a ...
1
vote
1answer
128 views

For an at-grade intersection of multi-lane roads, what are the (dis)advantages of a “turborotonde” or “turboplein” compared to a classical roundabout?

For an at-grade intersection of multi-lane roads, the "Turborotonde" (Dutch language Wikipedia article) or "Turboplein" (Dutch language wegenwiki article) is an alternative to the multi-lane ...
1
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1answer
103 views

How to calculate residual strength of a corroded structure from their stress values?

Currently, I have an actual entire corroded bridge model in the FEM analysis in Abaqus I want to estimate the residual strength of this bridge due to corrosion from the output results in the Abaqus, I ...
1
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3answers
172 views

How much force/torque act on a wheel of a vehicle when vehicle moves a constant speed and suddenly got a bump or jerk?

I am working on disturbance rejection technique in a vehicle of a wheel. Suppose our vehicle moves with a constant speed 15 km/h. Since roads are uneven in nature, suddenly vehicle got a bump or jerk. ...
1
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1answer
82 views

how would one calculate the % of heat not absorbed by a heat sink?

I'm planning on building a plant growth chamber inside a sealed/insulated 55 g rain barrel, and I'm trying to figure out how much of the heat from my lights will enter the chamber, and how much ...
1
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2answers
496 views

Whistle Design - Optimizing sound initiation pressure and volume

Assume you can use any whistle type, is there a way to choose the pressure point at which a whistle makes noise? For example I have a whistle that starts making noise at 2 psi but I would like to ...
1
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0answers
33 views

Best way to communicate data wirelessly with specific conditions

So I need two modules to give each other data with the following conditions: They are relatively short range. They need to be near each other to transmit the data, say around 5 cm. They are ...
1
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0answers
263 views

If I want to run an abaqus job (in Linux redhat) with user subroutine on parallel processors, how do I do that?

I work in Abaqus 2017 a lot. I have noticed that when I submit any abaqus job (that does not contain any subroutine!) via parallel processing (aka cpus=4 or 8), it runs just fine! But, when i submit ...
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2answers
148 views

Distribution of energy absorption in inelastic collision

Object A has mass $m_A$, and is travelling west with velocity $v_A$. Object B has mass $m_B$ and is travelling east with velocity $-v_B$. The objects collide in a perfectly inelastic collision so ...
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1answer
32 views

max shear act on point

Why we need to consider only 3 cases when we want to find the max positive shear ? IMO , We know that the max shear will only occur when the 67.5kN act on B , am i right ? There is no need to consider ...
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1answer
41 views

what is the range of the measurable relative elasticity with a commonly used strain gauge

I'm looking for a data that what is the typical application range for a common uni directional strain gauge like used in weight scales? I've read about around 200 ppm in a research gate article, can ...
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0answers
48 views

If I use clay tempering, can I take a thin piece of steel and make it hard as a very thick piece? [closed]

If I use the forging process of clay tempering, can I take a thinner piece of steel and and make it as strong as a very thick piece of steel? Getting the same strength, without the extra weight?
0
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1answer
203 views

Rule of thumb for choosing a best sampling rate

I have a discrete control system with known dead time and time constant, where a process variable is sampled at regular discrete time intervals and fed back to the controller. I want to find out an ...
0
votes
1answer
2k views

Is the mass flow rate constant in a thermodynamic cycle?

Is the mass flow rate constant in a thermodynamic cycle? More specifically a Rankine or Carnot cycle. For example if the mass flow rate of the turbine is 100 kg/s, is the mass flow rate for the ...
0
votes
1answer
2k views

shear stress at nail at different points [closed]

In this notes , i dont understand how the Q=(Ay) of the is considered ... I think the both Q at part C and part B should be = (60)(15)(mm^2) ... i have redrawn the structure , i am not sure whether ...
0
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2answers
61 views

Deflection In Multistory Structure

When analysing and designing a structure for the serviceability limit state the deflections of each beam must be found. When considering a multistory rigid jointed structure (as below) and applying ...
0
votes
1answer
460 views

Pump power and fluid viscosity

I used to calculate the power needed by a pump using Bernoulli equation, $ W =(p_2-p_1) + {1 \over 2}\rho(u_2^2-u_1^2) + g\rho(h_2-h_1) + R $ where $\rho$ is fluid density (and assuming it is ...
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2answers
22 views

Importance of equilibrium and compatibility equations in elasticity

What is the importance and relevance of equilibrium and compatibility equations in elasticity. What problem do they solve?
0
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3answers
302 views

Is battery-charge-stop-at-XX-percent circuitry not cheap? [closed]

I'm curious why IBM/Lenovo ThinkPad line is basically the only manufacturer/brand of mobility devices that includes circuitry and software that allows one to vastly prolong battery life of laptops ...
0
votes
1answer
241 views

Strain Energy Problem

A bar of length L and of uniform cross-section area A and second moment of area 1 is subjected to pull P.If the young's modulus of elasticity of the bar material is E,the expression for strain energy ...
0
votes
0answers
36 views

How can I attach a rotary encoder to a retractable string/wire? [duplicate]

I need to know how I can attach a rotary encoder to something string/wire that I can pull and it retracts automatically My idea was to take apart a retractable dog lead leash and affix it to it ...
0
votes
1answer
70 views

What signals are expected on the connectors for this 12V Volkswagen Scirroco wiper motor circuit

EDIT: added a picture of a very similar unit. I picked up a used VW rear? wiper motor that I want to use for a simple motion experiment. Having no idea how to power the thing I popped open the case ...
0
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0answers
40 views

Are there any turborotonde / turboplein designs with more than four exits?

For an at-grade intersection of multi-lane roads, the "Turborotonde" (Dutch language Wikipedia article) or "Turboplein" (Dutch language wegenwiki article) is an alternative to the multi-lane ...
0
votes
1answer
1k views

What is the reason for a reduction in entropy in a compressor

I was under the impression that the entropy reduction in a system only works with either mass or heat transfer. While I was researching intercooling of compressors I stumbled across a peculiar ...
0
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2answers
185 views

Thick walled cylinder theory - Stress/strain in ballooned out tube

I want to work out how much I can expand a piece of rubber tubing before it ruptures. The wall is 0.75mm and the ID 5mm. Hence I am working out the stress/strain from thick-walled cylinder theory ...
0
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1answer
53 views

Regarding automotive engine mounts

How are automotive engine mounts tuned to behave differently for different frequencies, like they are soft for high frequency low amplitude vibrations and hard for low frequency high amplitude ...
0
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1answer
91 views

Is a granite block tunnel longer lasting than reinforced concrete? [closed]

Assumptions Building Process exists Waterproofing is able to be replaced Notes Please answer yes or no with the science backing. This question is only about the strength and lifespan. This ...

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