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How many kWh this turbine would generate?

My grandfather and I are running some experiments down the river, however we don't have expertise in engineering so I bring up this question to the community and hope someone could help. How many kWh ...
Simple's user avatar
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1 vote
0 answers
583 views

How does the Xbox Series X "Heat-sink chassis" work?

I understand what a heatsink does, but I cannot wrap my head around how the newly announced Xbox Series X's heat-sink chassis works. From Xbox: Heat-sink chassis A heat sink is a non-electronic, ...
Davbog's user avatar
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0 answers
196 views

Given a BLDC motor with one shaft, where should I attach my encoder?

I have recently purchased an ODrive servo controller made for hobby BLDC motors. Since I had a BLDC motor at home, I did not purchase a dual shaft motor when I got the ODrive. My question is if I ...
user391339's user avatar
1 vote
0 answers
53 views

Half Sine Impulse in a modal Transient Analysis

I have a MDOF FEM model in which I perform a modal transient analysis based on the modal eigenfrequencies extracted in a prior step. I wish to excite only the first natural frequency of the system via ...
shoggananna's user avatar
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0 answers
31 views

Permanant extension for Fastener

I have a fastener with an accessibility problem. At the time of installation, the fastener is at the bottom of a crowded box with obstructions varying stiffness (Metal Plates and harnessing). It is ...
2NinerRomeo's user avatar
1 vote
0 answers
50 views

Considerations for switching from Conc. Sulphuric acid to Oleum

First off - this project is still in the early planning stages. The basic scope is that a plant want's to switch from using conc. sulphuric acid (~98%) in its process (nitration) to oleum. I ...
SimpleJack's user avatar
1 vote
0 answers
552 views

Is surgical and medical mask based on static electricity?

Is surgical and medical mask based on static electricity? By static electricity I mean like 3M N95 mask with at least two different layers of positive and negative static electrical layer. I googled ...
Superuser's user avatar
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1 vote
1 answer
562 views

How to calculate the required torque for an azimuth/elevation antenna rotator?

I want to build an antenna rotator for a 1M dish. How do I calculate the required torque for the motor of the elevation axis? Here's a sketch of the problem: If the "bottom" of the dish is the pivot ...
hjf's user avatar
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0 answers
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flexing operation fails when structure is too long

I have a linear repeat such that for up to 11 repeats, the flex operation works perfectly. for 12 and more, the operation goes haywire. is there an alternate way of doing it that avoids this ...
juggler's user avatar
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1 vote
3 answers
189 views

Some questions about the specific speed (Ns) of hydro turbines

So we all know the basics behind specific speed Ns of hydro-turbines. $$N_s = RPM \cdot \frac{ \sqrt{(P)} }{ H^{1.25}}$$ where P is the power output and H is the head. The theory is that once you ...
sithvincent's user avatar
1 vote
0 answers
130 views

RSS Tolerance calculation and usage

From my experience, I've been calculating RSS tolerances by squaring all relevant tolerances, summing them up and then square rooting the sums... ie: RSS=[Σ(tol^2)]^0.5 I've also heard of other ...
Philip C's user avatar
1 vote
0 answers
231 views

Equivalent moment of inertia in a crank-rocker mechanism

I'm attempting to model a crank-rocker mechanism (see picture). A motor is connected to the crank side and is driving the mechanism with a torque $\tau_{motor}$. A load is attached to the rocker side ...
Filip Karlsson's user avatar
1 vote
0 answers
82 views

Launching a ball with springs or with elastic bands

I’m a student and have to create a machine that can launch a small bowling ball to knock over some pins. I was thinking that I could use elastic potential energy to launch the ball but I’m not sure ...
KMarien's user avatar
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1 vote
0 answers
26 views

Standards for safety car seatbelts locking condition

Is there an (international) standard which determines the condition when a car seat belt locks? Which standard is it? Does the standard determines a speed in m/s of the belt, such that it locks if ...
Sarah's user avatar
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1 vote
0 answers
167 views

Reference book for hydraulic systems design

I'm looking for a good reference book on the topic of fluid dynamics/hydraulics systems engineering. I'd like a reference for simlpe/estimate calculations on things like major losses (pipes), minor ...
Jacob Bitsch Nørgaard's user avatar
1 vote
0 answers
196 views

Wobbling DC motor head

I have used 250 watt DC motor, for DIY electric potters wheel. Motor rated with RPM 3300 and geared reduction to 330 RPM. The issue I am facing is wobbling of the motor head. This issue is with the ...
aashunkon's user avatar
1 vote
0 answers
86 views

Bevel gear friction and inertia calculation

I want to calculate the friction and inertia between 2 bevel gears with straight teeth. I know how to calculate those parameters between regular gears with straight teeth. Is there any difference for ...
Nick Chernuha's user avatar
1 vote
0 answers
25 views

What is the best way to find solved problems similar to the one at hand?

This is a general question, so sorry if it breaks the rules. However, I think it is very important as more often than not someone else has already solved a similar problem that can be applied to solve ...
Pekka's user avatar
  • 34
1 vote
0 answers
30 views

Slow integration of system ODE under specific conditions in adsorption problem

I am trying to solve the system of ODEs below. I am applying the finite differences to z, so I get a system of ODE that I can solve with a solver like ode45. The problem is that under the conditions ...
Synergix's user avatar
1 vote
0 answers
95 views

Clutch for high-speed operation (>40 000 rpm)

I'm currently working on a setup where at some operations my motor has to drive a shaft up to the motor's maximum operating speed (12,000rpm) and a torque of ~0.14Nm but at other conditions this shaft ...
steinc's user avatar
  • 11
1 vote
0 answers
45 views

Is there a standards organization or methodology to determine the elastic material properties of common materials?

Is there a standards organization or methodology to determine the elastic material properties of common materials? What constants are normally used to define these properties? More specifically, the ...
wyer33's user avatar
  • 121
1 vote
0 answers
313 views

Tolerance Analysis on clearance holes

I am designing an enclosure that holds a lens (clearance fit) and a photodiode on a PCB. The alignment of the photodiode to the lens must be pretty tight, thus I am using a boss on the enclosure (also ...
Philip C's user avatar
1 vote
0 answers
129 views

Efficiency of harmonic gear drives

Does anyone have application experience with harmonic gear drive efficiencies as opposed to planetary or parallel axis reduction systems? I'm looking into drives with about a 25:1 reduction, and it ...
jko's user avatar
  • 2,347
1 vote
0 answers
29 views

Water distribution through N x Needle orifices

Consider a water distribution setup consisting of a feeder line blocked at one end but having 100 needle outlets all the same size. The feeder line cross sectional area is much greater than a needle ...
Osmium's user avatar
  • 11
1 vote
0 answers
26 views

Axis connection types

Complete hobbyist here. I have two questions I have a problem figuring out. I have hard time finding information about axis and types of connections they have. For example take this worm gear reducer: ...
somerandomusername's user avatar
1 vote
0 answers
322 views

How can I calculate the shear modulus (Gxy) for the material of a composite laminate [10/-10/-10/10] using test data?

I have the data from a tensile test including axial displacement, force, and strain, as well as E1, E2, Nu12, and Nu21 for the carbon fiber prepreg. I am trying to use this axial data to calculate Gxy ...
Renato's user avatar
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1 vote
0 answers
48 views

Calculation for lowering temperature in a room… room-fridge with water mist?

I was looking at how the water cools my body when it evaporates off it. Then I thought the specific heat capacity could be used to calculate how much energy (i.e heat) would be taken out of a room ...
El Flea's user avatar
  • 98
1 vote
1 answer
23 views

How do cavity resonators differ from tubes of uniform width?

I read that wine bottle produces sound when u blow sideways onto its rim because some frequencies of the white noise produced in your mouth gets amplified when they match the natural frequency of the ...
never took courses but why's user avatar
1 vote
0 answers
32 views

How do I correctly model this system of torsion springs?

I am currently designing a symmetric parallel mechanism that can be modeled as follows: Here, $\tau^j$ denotes actuator moments and $k_i$ are torsion springs constants. For a specific point in the ...
Skydiver's user avatar
  • 245
1 vote
0 answers
79 views

Strut Angle Vs Overhang

I have a 10mm metal disk that is 1mm thick. It is easily bent when a force is applied (green arrow) to the unsupported edge. I need to add a strut, but at what angle? The part is weight-sensitive, ...
EricP's user avatar
  • 111
1 vote
0 answers
63 views

Can any Air rotameter be used for refrigerant gas by using equation conversion?

Currently, I am trying to find rotameter calibrated for R134A gas flow. However, most companies only sell rotameter or variable area flowmeter for water/Air/Nitrogen flow. Is it possible to use any ...
HENG KIM RUI's user avatar
1 vote
0 answers
221 views

Shore durometer type D to brinells

I saw a video where a person was measuring hardness of a material with Shore durometer type D and was comparing it to steel. The screen on durometer showed 96.5 HD and I was just wondering, how much ...
RotV's user avatar
  • 111
1 vote
0 answers
23 views

Why is a mold required in isostatic pressing after performing Sintering

After an a object is formed through direct laser sintering, as a post-processing procedure the object is sent for hot-isostatic pressing, In hot isostatic pressing the sintered object is placed in a ...
Somanna's user avatar
  • 159
1 vote
0 answers
167 views

Calculating reliability of a parallel redundant system

I'm trying to calculate the reliability of a system that has proven to be a bit more complicated than I thought. Here is the block diagram for the system: Every single component in this diagram is a ...
trevinator's user avatar
1 vote
0 answers
20 views

Software for Soft Body Dynamics

I am searching for some software to simulate the behaviour of soft bodies like cheese in an quantitive way. For example I want to know the forces in the body during the simulation. I thought of ...
Hell stormer's user avatar
1 vote
0 answers
36 views

Solar Radiation Environmental Test Duration

I am designing an outdoor sensor and I need to test it for continuous outdoors service. One of the test I wish to perform is a solar radiation test for the actinic effect (like procedure 2 in MIL-STD-...
Eli's user avatar
  • 19
1 vote
0 answers
21 views

Questions on Na2Cr2O7 turning to a vapor phase in 2500F furnace. And possible ways, if any, to filter it

I've looked for answers without success, so turn to the experts. At air temperature, solid-phase sodium dichromate (Na2Cr2O7) -- or the equivalent, sodium dichromate dihydrate (Na2Cr2O72H2O) -- is ...
Daniel Forbes's user avatar
1 vote
0 answers
28 views

Meaning of SNR in Instrument Specifications

I am evaluating the specifications of an FTIR instrument (Bruker Vertex) and came across the following statements/items: Signal-to-Noise 5 sec sample, 5 sec reference: >10,000:1 (<4.34 x 10-5 ...
bebissig's user avatar
1 vote
0 answers
17 views

how to get more number variance compared as the csv output file of two model stl files in Cloudcompare

we are using the CloudCompare for comparing two mouth STL model for Final doctoral theses, like works done in this paper(pdf) shown blow: and the instruction said here: so i have tried to insert the ...
Soheil Paper's user avatar
1 vote
0 answers
98 views

In Nastran, how to ignore fatal error due to failed convergence and move on to next subcase?

At the moment the whole analysis stops when 1 subcase fails to converge. How can I keep the analysis going such that all subcases are are run, even if they all might produce an error? I'm pretty sure ...
Jeroen's user avatar
  • 67
1 vote
2 answers
163 views

BJT Output Characteristics Question

Ok, so I am pretty confused at the moment with a question that I have been given to work out by my lecturer and was wondering if I could get some guidance with it. I will attach images of the question ...
Meckx's user avatar
  • 21
1 vote
0 answers
22 views

how do you calculate viscocity from torque arm load cell measurements?

I have a piece of company developed equipment that uses a pot mounted on a rotating base plate with a 0.15m torque arm and load cell, a mixing paddle is used to stir the mixture while the controller ...
Chris James's user avatar
1 vote
0 answers
39 views

Design of fan pipe for propelling glitter

I am trying to create a prototype for a glitter shooting mechanism. It is worth mentioning that I have no experience with mechanical engineering or fluid dynamics. I think the below image describes ...
DanNicolau's user avatar
1 vote
1 answer
480 views

Static electricity in PE foam rolling

In a PE (polyethylene) foam factory there have been some incidents with static electricity that have created minor fires. Fire is a concern in such a factory, as PE is highly flammable, and even more ...
PavoDive's user avatar
  • 175
1 vote
0 answers
3k views

How to calculate the flow rate of a gas through a pipe?

I am trying to calculate the flow rate of Nitrogen through a cylindrical pipe. I only need a ballpark value, and the only information I have is the inlet pressure as 15 psig (assuming the same ...
eenz's user avatar
  • 23
1 vote
0 answers
57 views

I hope this is the correct forum for temperature related question

I have about (this is experimental) 0.75 to 1 liter of water. Ive found I can use 400W of power through peltiers to reduce water flowing through at 1L/minute from 32C to 20C in about 1 to 1.5 minutes ...
Paul Pease's user avatar
1 vote
1 answer
68 views

Does the surface roughness play any role in shock absorbing?

Consider a mass of about $130 \pm 10 $ kg, falls from height, let say $2.5 $ m. In order to dampen the vibration and sound, I use silencer or drop pads. I was wondering if introducing the macroscopic ...
user avatar
1 vote
0 answers
47 views

What purpose do the "angled tabs" on a PCIe bracket serve?

In the PCIe specification (see page 75), the "short arm" of the bracket has two cutouts; one for the slot that the retaining screw fits in, and another square cutout that has additionally had the ...
Matthew's user avatar
  • 111
1 vote
0 answers
25 views

Oil pressure inside copper tube?

**Background ** I'm struggling finding how to calculate the pressure that occurs within my system and then once calculated I need to reduce that pressure. My system I have a 1 inch copper pipe ...
Eric F's user avatar
  • 205
1 vote
0 answers
29 views

How can I find the length of 12 gauge wire needed for a cone of if I know it's surface area

So I'm working on a personal project, and I need to figure out how much 12 gauge wire (which is ~2mm thick) I would need to cover a cone shaped rubber core, which has a surface area of roughly 3,417,...
Fæowölf's user avatar

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