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1500 questions
5
votes
2 answers
Upper bound for von Karman Vortex Street?
I'm trying to see if I can find any literature on this specific question, but a few days of scholarly digging has been fruitless.
Given a 5" round pipe with a bluff body inserted, is there an upper bound for the Reynolds number at which the von…
Ramrod
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5
votes
1 answer
Optimal size and shape for a steel target?
Problem
I'm building a steel target for long-range rifle shooting. For those unfamiliar, the purpose of the steel is to produce a loud "PING" when the bullet strikes the target. It's very fun.
Since I have a variety of materials to choose from, I'd…
Hundley
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5
votes
1 answer
How do engineers deal with sinkholes?
Sinkholes have been known to occur in the middle of cities or other locations where they affect buildings:
Some areas are more prone to sinkholes than other areas because of the presence of old mines or limestone bedrock. Even in these areas where…
hazzey
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5
votes
6 answers
Why don't public transport networks have more routes to each terminal?
When using public transport, we often need to change routes in the middle of the journey. These changes have costs – I can think of the following, but there may be more.
If we're reading, working, etc. on board, we need to take a break, losing…
Yngve Høiseth
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5
votes
3 answers
How to select a low flow rate diesel flow meter
I need to select a precise flow meter for the following application condition:
Flow range: 0-150 liter per hour
Medium: Diesel
There are so many meters on the market that I am a bit lost. How do I determine whether a flow meter is acceptable for…
Maruf Hossain
- 51
- 2
5
votes
2 answers
Is there a theoretical bound to how tall a structure can be built?
Assuming that there are no constraints on cost, land to develop, or supply of materials, is there a theoretical limit on how tall a structure can be built? What are the main physical constraints that limit the tallness of structures?
I emphasize…
Paul
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5
votes
1 answer
Von Karman mixing length $l=k \frac{du/dy}{d^2u/dy^2}$
In a fully developed turbulent flow of an in-compressible fluid inside a pipe of radius $R$, velocity at the center is $U_m$. If we define $U^*=\sqrt{\tau_0/\rho}$, where $\tau_0$ is the wall shear stress and $\rho$ is the density, then find the…
Ghartal
- 159
- 4
5
votes
2 answers
How to mount timing pulleys/belts for small DIY project
I'm building a rotating lamp for a small DIY project to learn about motors and timing belts/pulleys. As I am learning, finding parts that are small enough, fit a stepper motor shaft and reasonable priced is difficult.
I am trying to find a way to…
jeremy
- 51
- 2
5
votes
2 answers
Weight Sensing Problem: Need to detect 10kg load down to milligram accuracy
I need to build some type of scale where one can place four 600mL beakers on it and measure out its weight down to a milligram level of accuracy. I'm doing this so I can dose a very small amount of liquid (2 microliters) into the beakers at a time.…
AndrewP
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5
votes
5 answers
What colour of tarp will let in the least amount of heat?
Source: Low Tunnel Construction: How to Build a Mini Hoop House
I have a small greenhouse that I want to keep as cold as possible in the spring. I plan to cover the greenhouse with a polyethylene tarp to shield it's contents from the sun.
However,…
User1974
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5
votes
1 answer
Byte organized and Word organized memory using memory modules
I'm currently learning about how a CPU works on the hardware level and something that keeps coming up is memory organization. From what I've learned (and please, do correct me on anything that is not right), you can have a memory organized in the…
user12377
5
votes
1 answer
Mechanical vibration of objects
Do you happen to know relevant references in the literature that model the mechanical vibrations of a solid object (preferably antennas) by means of complex representations as a function of time?, i.e. can we say that the radial displacement can be…
Jeremy
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5
votes
0 answers
Flow through flattened tube
Is there an analytical solution for the Navier Stokes equation for flow through a flattened tube ( flat plate in the center and semicircular lobes at the end).
fluid_123
- 51
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5
votes
2 answers
Applications of Thermodynamics
I am trying to solve this but I am stuck; I have watched loads of YouTube videos but still don't understand how to complete it:
A mass of $m=0.12 kg$ of air has an initial temperature of $T_1=500°C$ and pressure of $p_1=0.8 MPa$. If the air is…
Kyle Anderson
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- 9
5
votes
2 answers
How to calculate the pressure loading of a vented silo explosion?
I would like to independently check a vendor's silo design for proper explosion venting. Worst case, it is essentially cylinder filled with a stoichiometric mixture atomized sugar dust and atmospheric oxygen initially at atmospheric pressure. The…
ericnutsch
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