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26 views

Horizontal flanged connection in an atmospheric container

I have a round container that is open to the atmosphere. Vertical flanges see the hoop stress from the content as main tension force. We typically have Dead Load, content, Wind and Seismic loads. ...
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0answers
14 views

DC Inverter motor AC utilization category

I am looking at specs of an air conditioner unit. It uses DC inverter technology and maximum current listed as 21.5A So are DC inverter motors considered resistive or inductive? What utilization ...
1
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2answers
41 views

How to calculate the speed and force of the piston in a vacuum syringe?

Suppose i have 4 empty syringes. And by empty i mean they were having the air sucked out of them, and they "contain vacuum". Assume the head of the syringe is blocked so vacuum can be formed. I want ...
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0answers
11 views

Does the air cushion on which the original hyperloop will sit require energy constantly or not

Does the air cushion on which the original hyperloop idea envisioned by Elon Musk require energy constantly to keep afloat, as the hovercraft does or would it be designed as the modern air suspension ...
1
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0answers
16 views

Zero-state observability and strictly passive systems

I'm currently studying passivity theorems of nonlinear systems, and I find it difficult to understand the difference between the different kinds of strict passiveness. Are there any intuitive ...
1
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1answer
28 views

Can anyone explain calculation of net force due to pressure in a streamtube of fixed control volume and infinitesmal size

I am studying derivation of bernoulli equation from FM White's fluid mechanics and in that pressure distribution is as shown in the image 1. I am unable to understand force calculation as shown in ...
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0answers
28 views

Offline Parameter Estimation for second order system - Ordinary Least Squares

I have a second order system which is described by the following differential equation: $\ \ddot{y}+α_{1}*\dot{y}=b_{0}*u $ where $\ y $ is the output of the system and $\ u $ is the input of the ...
0
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1answer
39 views

Artificial gravity with accelerating elevators enclosed in a gigantic sphere

If we could be able to construct a gigantic hollow sphere, multiple elevators/chambers can glide in the interior of the sphere, accelerating and decelerating without colliding, providing artificial ...
1
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1answer
26 views

(moulded) cast properties of the untreated surface

While my research about the untreated surface of moulded cast I read that the properties such as tensile strength, 0,2% proof stress and so on are different (much smaller) from the properties you can ...
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0answers
11 views

Standing wave node counter

I have a an assignment to complete this Term, the assignment consist in making a machine that would produce standing waves in various frequencies, (for example the typical motor connect to a string ...
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2answers
19 views

Sylvac UL 4 - USB - (Send data) reports 'no.data'?

Using the sylvac UL 4 Each time I invoke the (send data) function the sylvac LED panel reports 'no.data'. To mention the obvious but nothing is received at the connected USB device. My question ...
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2answers
35 views

Voltage at node A respective to the ground

I want to calculate the voltage at node $A$ respective to the ground. $R_1=1.8\text{k}\Omega, R_2=3.8\text{k}\Omega, R_3=1.8\text{k}\Omega, R_4=5.8\text{k}\Omega, R_5=2.4\text{k}\Omega$ and $V1=4.3V, ...
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0answers
21 views

Blower-door test: should we calculate its output during sizing of the heat exchange ventilation?

A human needs ~30m3/h fresh air. Our 100m2 house is occupied by 4 humans, so 4 * 30 = 120 m3 fresh air needed. A blower-door test says at 50 Pa, max 60% of the air in the house can be exchanged (...
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3answers
98 views

DOE analysis or root cause analysis?

For any testing that a part is suppose to pass a test, let's say the leakage test of a seal flange. How should I individualize the cause? I know there is root cause analysis and for different ...
0
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1answer
16 views

Sieve trays used in Liquid liquid extraction tower instead of bubble cap and valve trays?

In an LLE operation pilot plant, i saw that sieve trays are used instead of bubble cap and valve trays... In LLE operation, they require good mixing, so i was shocked why bubble cap and valve trays ...
2
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0answers
23 views

Is there any software for testing cad model waterproofing and isolation?

I have a cad model of a plastic box that is made of two parts. Two parts are connected with resin isolation. I want to test if my part is at least in theory ip86 water-resistant. So is there any ...
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2answers
36 views

Designing a loaded voltage divider?

I was wondering how to design this circuit in depth, since I have no idea what to do.
0
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1answer
52 views

Circuit analysis, voltage in and voltage out

I want to solve $V_o$ in terms of $V_i$ from the following circuit. $R_1=95.7 \Omega, R_2=9.1 k\Omega, R_3=1.0 M\Omega$ So the solution is form $V_o=kV_i$ and I want the factor k. I know that:...
0
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1answer
52 views

Why is it bad to run power through BNC (RG58) cables?

A standard practice in many academic labs, which I'm told is "bad practice", is to use RG58 cables (i.e. standard BNC cables) for power distribution. Question 1: Why is this considered bad practice?...
0
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1answer
21 views

Leaky NPT fixes

At my current role we have a hell of a time trying to get NPT threads to seal. We avoid them where we can but sometimes its just faster and cheaper to spec and buy parts with NPT threads. We are ...
0
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0answers
26 views

Can Flowmaster be used to model an entire pipe run?

I just started using the Flowmaster program (ver 08.11.01.03 if relevant) to model a series of stormwater pipes which are almost certainly in a pressure flow situation based on a first round analysis ...
0
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1answer
14 views

Lift and drag force measurement in a flume

I'm trying a test a hydrofoil in a low Reynolds flume, but struggling to find a way to mount the hydrofoil in the flume and measure the lift and drag force. I have some idea of using a load cell but ...
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0answers
20 views

Boundary Layer Problem Submarine

A submarine can be assumed to have cylindrical shape with rounded nose. Assuming its length to be 50m and diameter 5.0m. Determine the total power required to overcome boundary friction if it cruises ...
0
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1answer
20 views

Faster car drifting (motorsport) when using limited slip vs welded differential

I have been drifting RWD (rear wheel drive) cars for some years now. I tend to think about every engineering solution that other drivers use and how does it work before applying it to my car. What ...
2
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0answers
26 views

Injecting CO$_2$ into water: how does injection work?

I've been wanting to design my own water carbonation device for a while. For reference, I've been looking at devices like the Sodastream, which injects pure CO$_2$ into water to dissolve it with up to ...
0
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0answers
9 views

Toggle position of a fourbar slider-crank

In the fourbar mechanism as in the following picture, I have to find the toggle position, the sliding distance and the time ratio. Here is my understanding/plan to do this: The toggle positions ("...
1
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0answers
11 views

Network Switch with Togglable Ports

I'm a software engineer that works on custom embedded devices. I program these devices through a typical RJ-45 ethernet cable. In most cases, I can connect my computer to these devices through a ...
2
votes
1answer
27 views

Using GPU Acceleration in ANSYS Mechanical

I am attempting to solve ANSYS mechanical (via workbench) using GPU acceleration, but I keep getting the following error: * WARNING * CP = 79.594 TIME= 15:40:08 ...
0
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2answers
47 views

Why does stress act a point instead of on an entire area normal to the stress?

I've often heard stress acts at a point and not on an entire cross-sectional area to which the load is applied normally. Im a little confused here, Let us consider an area of cross-section ...
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0answers
25 views

Why is it better to filter off several smaller batches than one large batch in a batch filteration

Why is it better to filter off smaller batches than one large batch for wet cake filtration in a peeler centrifuge?
2
votes
1answer
14 views

How do multiple enphase microinverters stay synced to the grid?

In a prior question it was established that any string or microinverter that is grid tied must put out sinusodial power. But there is also the task of being in sync with the grid. It seems from ...
1
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0answers
24 views

what does 775 mean in a 775 dc motor? [closed]

I don't understand sometimes what numbers actually mean in some naming conventions of many types of motors. Is there a good repository of knowledge regarding this subject except for those boring books?...
0
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0answers
25 views

Continuous vs Discrete system simulation in Python

Normally, when you discretize continuous system with zoh method, your continuous system output with the corresponding discrete inputs passed through zero-order hold should be the same at sampling ...
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0answers
31 views

How do you calculate consumption given standard values in pneumatic cylinders (ISO 155552 Standard)?

The values I was given are: Force of advance= 50 kgf Total displacement= 3 cm Displacement= 45 seconds The Standards table I was given shows kgf/cm^2 so I should do 50/(3^2) right? Which is 5.6 ...
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0answers
15 views

Programmable motion on a metallic planar surface

This question is based on just a vague imagination. I am wondering if there is some way to programatically, make an object move on a planar surface in arbitrary paths (curved , swiggly lines etc) (not ...
0
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2answers
25 views

How to keep a symmetric-lens-shaped object upright using only wire?

Given a lens-shaped frame with a single crossbar running parallel to the floor, how could we keep that object upright and stable on one of its endpoints using only wire? The shape I'm describing is ...
0
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1answer
34 views

How to compare multiple data acquisition systems?

for an application of displacement measurement under 1 kHz, I have 3 options to choose from. the application is automotive. unfortunately I don't have deep electronics knowledge and the catalogues ...
0
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1answer
28 views

Can you focus a 300W LED to a small area?

I want to focus a 300W LED into a small area, about 5mm in diameter, much like focusing the sun's rays with a fresnel lens. I have to be like 2 meters away from the LED to focus the LED light with a ...
0
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0answers
12 views

phase loss detection

Hi I use this circuit to detect phase loose, so if one of the phase lost , the phase loss signal will be high, the problem in this circuit are. 1-if the input voltage less at 50% it give phase loss , ...
1
vote
2answers
49 views

Difference between lead screw and worm screw?

I am confused whether a lead screw and a worm screw are the same exact thing. In my engineering workshop lab, they come up as separate things. For example, a worm screw is there in the indexing head ...
0
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2answers
58 views

What is the actual stress in a certain point in a body?

I'm reading my book on strength of materials and it says that the stress in a point depends on the orientation of the section that we are observing, and since there are infinite number of section that ...
1
vote
1answer
44 views

Can the core of electrical transformers be made solely from copper?

Most electrical transformers that I am aware of have either copper or aluminum cable wound around an iron core. Can the iron core be replaced with a copper core? Would there be any performance ...
0
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0answers
20 views

Translation of vibrational motion in the 15-20 Hz range

Is anyone familiar with how to create a "shaking" fluidized bed. With vibrational amplitude in the 2" range and Hz 15-20? I'm constructing a vibrational fluidized bed dryer for the purpose of drying ...
0
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1answer
17 views

On partial reboiler and total condenser in distillation column

Why is it that a total condenser and partial reboiler are used in a distillation column and it is not the other way around?
0
votes
1answer
17 views

Designing a “ratcheting” spinning wheel with ferrous metal bits

I'm trying to design a freely spinning wheel that will "lock" into a few different configurations. I'm planning on placing a rare earth magnet near a certain point on the wheel, and inserting bits of ...
0
votes
1answer
20 views

Elastic Modulus in Arbitrary Direction for Orthotropic Material

Suppose I have a material with an elastic modulus of Ex in the x direction and an Elastic modulus of Ey in the y direction. How would I find the effective elastic modulus in an arbitrary direction (...
1
vote
1answer
35 views

Help me build a mechanical gizmo involving a pulley (I think)

Electrical engineer here. I'm looking to build an incredibly simple mechanism that in my mind involves kind of a pulley. Below is a diagram. So it's essentially like a mechanical servo. I would like ...
0
votes
1answer
21 views

Azeotropic Distillation - Am I interpreting this VLE diagram correctly?

I've been looking at ways to re-concentrate a formic acid-water binary mixture with the VLE diagram below. Am I correct in saying that to concentrate a solution of say , 40% formic acid by weight I ...
0
votes
0answers
21 views

Design implementation of centrigual blower / compresser impeller - inlet/outlet ratio

I am designing a 3d printed impeller to go on my dust extractor, but while there is good data about the differences between forward/radial/backwards curved blades, there is very little on the best ...
-1
votes
1answer
24 views

I need a valve siphon or device to empty a boat that doesnt need a battery or power

Maybe something cool actually exists. Something clever. I was actually thinking of an hydraulic ram but im not sure it's a good idea. Another thing i saw was a one-way check valve. Would this work?

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