All Questions

-1
votes
0answers
12 views

explain the inlet valve mach index and the mean piston ratio

this is the attire i wear during practical day in the university. The white shirt is an overcoat which I wear and the goggle is worn to protect my eyes from any particles from entering my eyes during ...
0
votes
1answer
9 views

Glass used in biometric machines

I would like to know what kind of glass is used in biometric attendance machines over which we press our thumb? Is there something special about these glasses or their manufacturing?
0
votes
1answer
15 views

Contradictory result for mass balance

I solved this problem by doing a mass balance for the mixing chamber and an energy balance for the water heater and the mixing chamber as follows: $\dot{m}_{\text{mix}}=\dot{m}_{\text{Tank}}+\dot{m}_{...
0
votes
1answer
18 views

Are there any science fair ideas that concern designing or creating something that had a benefit? [on hold]

I am looking for science fair project ideas and am interested in any branch engineering. Would you have any ideas for a science fair project? I am in grade 10.
0
votes
0answers
21 views

What is an engineering term for this type of arm

I'm trying to describe a part - it's an arm that holds an axle sleeve (which ultimately holds a wheel). I'm stuck right now describing it simply as a "wheel arm", but was wondering if there was some ...
1
vote
0answers
18 views

Polyurethane with microbial resistance properties

I'm looking for a polyurethane with microbial resistance. Doing some research I found two commercial types: DESMOPAN 9392A and DESMOPAN 2792A. Both are manufactured under GMP conditions and limited ...
0
votes
0answers
20 views

What is the difference between PET bottles and PP Bottles?

Good morning. I'm currently researching the differences between PET bottles and Polypropylene bottles for my industrial engineering thesis. I'm currently designing a business model for a company that ...
0
votes
1answer
43 views

Can you help interpret hand-drawn technical drawing?

I can't seem to figure out the proper left view for the following image, and the full and half sectional cutout for the left and front projection.
0
votes
1answer
46 views

stress strain curve properties analyse

There are two components given with each stress-strain curve. Determine the component that maximise the load carrying capacity and that maximise the elastic deformation per unit applied load. Is it ...
0
votes
1answer
32 views

pressure loss in a T fitting

For weeks I have been searching internet , but still unable to find answer , so here it goes: I have to calculate pressure losses in heating circuit , and am stuck at calculating losses in T fittings. ...
0
votes
1answer
27 views

Electronics confusion

I want to build my own off-grid system but confused with what sizes (V, I) to get. I want to run a 24v system powering 4.4kWh/day. I have 4 hours of usable sunlight a day and space for panels and ...
1
vote
0answers
30 views

Does containing explosives in a metal cassing make a bomb stronger or weaker? [on hold]

Does it allow pressure to build up until it ruptures like a pressure cooker with a blocked safety valve? Or does it absorb some of the energy in order to deform the metal? Or is it's net effect ...
0
votes
1answer
12 views

Best balance of electrical and pneumatic control lines in CNC router table?

I'm building a 4' x 8' gantry-style CNC router table. The spindle motor uses pneumatics to power its draw bar (for automatic tool changes). There are three separate pneumatic supply lines that go to ...
0
votes
1answer
27 views

Solar Thermal heat gain formula converted to CO2e and trees saved

We have invented a solar thermal heating system with interseasonal storage, recently patented. I want to display the trees saved and carbon offset on the control display based on temperatures coming ...
0
votes
0answers
28 views

Product as a type vs product as particular item

Quality standards of 9000 group widely uses "product". What exact meaning does it have? Is it the product as a model or particular unit with particular id?
0
votes
1answer
32 views

Model Reduction - ANSYS

I am trying to reduce my model in ANSYS using Craig-Bampton Method. My ultimate goal is to read system matrices, stiffness, damping and mass matrix with MATLAB. I have been researching for a while, ...
1
vote
1answer
41 views

Resolution of forces and state of stress at a point

Is resolution of forces similar to expressing a vector as a linear combination of some other vectors in linear algebra? Similarly, Is the state of stress at a point in 3D similar to expressing the ...
0
votes
1answer
24 views

Curve-linear vs. Cartesian coordinate systems: linear-elastic & isotropic elasticity tensor

For shell elements, is the elasticity tensor for linear-elastic & isotropic materials the same in a local curve-linear (convected) system vs. a local Cartesian system? I wonder because ...
2
votes
1answer
39 views

Would pumping down (below 0 psi) on a gas cylinder regulator cause it to break?

Would pumping down on a gas cylinder regulator cause the needle of the valve to break since it’s trying to go below zero? Would this also cause a problem with the regulator itself? I’ve included the ...
2
votes
0answers
27 views

hot wire anemometry

Hot wire anemometry can be used to measure the temperature of a wire in fluid flow. The voltage fluctuation across the wire is used in conjunction with an energy balance on the wire to obtain the ...
0
votes
0answers
13 views

hydro aspirator design parameters

I am looking for design equations, or reference designs in order to maximize the vacuum created by an hydro aspirator such as the one pictured here. https://en.wikipedia.org/wiki/Aspirator_(pump) ...
0
votes
0answers
19 views

Observed activation energy of parallel and sequential reactions

I saw this sentence in a test: Observed activation energy, $E_\mathrm{obs}$, increases with increasing temperature for parallel reactions and decreases with increasing temperature for sequential ...
0
votes
0answers
24 views

How to get value of K1 and K2?

I am working on Passivity based controller of boost converter and refer below paper. https://drive.google.com/file/d/1S2Yql5dM3TzbiW14VqV20kZVt6BUgx7b/view?usp=sharing you can see paper. i try ...
-1
votes
1answer
29 views

In equilibrium is engine torque zero? Vehicle dynamics

Consider following equations for a driving wheel in a car. $$ J\dot{\omega} = T - F_x R - F_r R \\ m\dot{v} = F_x + F_r $$ where $J$, $\omega$, $T$, $F_x$, $R$, $F_r$, $m$, and $v$ are wheel inertia, ...
-1
votes
1answer
18 views

Solving parallel without GUI in batch mode not working as expected (Linux)

I'm currently trying to run my solutions in batch mode because in the future I'll be running simulations which I want to be done in the background. I've tried to adapt the code from here: https://www....
0
votes
0answers
20 views

How is the liquid refrigerant distributed throughout an AC system before start [on hold]

When an air conditioning system is at rest (eg before starting) how is the liquid refrigerant distributed throughout the system? I would think that the expansion valve would remain slightly open, ...
0
votes
0answers
14 views

What is the pitch angle squared representative of?

I am working with a sensor which gives me a tilt reading in degrees and I have been observing the waveform in the frequency domain using MS Excel 16. I was curious as to what the units would be for ...
2
votes
2answers
58 views

Viscoelasticity and Hyperelastic model, history and difference

Actually, I see some papers use viscoelasticity or hyperelastic model for the same materials. It seems to me that those models were invented in different eras, and the hyperelastic is a newer model ...
-1
votes
0answers
30 views

what is the most efiicient way to mill/ machine a spherical and pancake ish structure as seen in the figure?

The overall dimensions for rectangular block: 8” x 3” x 2”. Ball should stay the longitudinal center line of rectangular block Bottom pancake feature should stay lateral center line of rectangular ...
2
votes
0answers
15 views

Does a closed loop biomass-fired cogeneration/CHP make sense?

I'm working on a project concerning electricity production using biomass, and we have seen that making use of cogeneration is very attractive in order to increase the efficiency of the installation. ...
0
votes
1answer
39 views

Pathway for drone racing

How can I build a v shaped pathway for drones? It would be a sort of racing path and there would be multiple drones flying over the pathway at the same time. The race would be a relay race. So there ...
1
vote
0answers
34 views

Flow of hot gasses around the pipe

I have the following problem: there is a copper pipe getting through a wooden wall. On one side of the wall (hot side), I have elevated temperature which is defined by radiation and convection. On the ...
1
vote
1answer
29 views

Meshing Complex models in abaqus

I'm trying to mesh a model of a morphing wing in Abaqus and have been running into issues. It was recommended that I partition the model into smaller parts, but it seems that the more I try to ...
0
votes
1answer
51 views

Which container orientation, if any, can hold more weight?

These are cross sections of identical shipping containers, except one is rotated 45 degrees. The cross sections are squares, 3 meters to a side. I drew dashed lines to show where they're suspended by ...
1
vote
4answers
565 views

Dimensions for CNC machining

Creating a drawing for a part that will be CNC milled. Should all of my dimensions come from a baseline on the part, like an edge or is it ok to use Centerlines? See yellow highlighted dimensions ...
0
votes
1answer
20 views

Solving 1D Unsteady Homentropic Flow using Method of Characteristics

I am looking to solve the 1D Unsteady Homentropic Flow equations using the Method of Characteristics (MOC). I am using Zucrow and Hoffman's Gas Dynamics Volume 1 as a reference and I am currently ...
1
vote
0answers
20 views

Maintaining constant speed of a CVT engine during a slope

I am not sure if this question is related to this community. But nevertheless. I work on CVT engines, I had a new idea of modifying my controller during a slope or a gradient on the road so that the ...
2
votes
1answer
606 views

Why are tunnel boring machines not using cone-shaped drills?

The surface area of the head of a tunnel boring machine is usually flat. A cone-shaped head would increase the surface area. The question is if it could speed up the boring process. I know that with ...
4
votes
1answer
53 views

Easily compute a good approximation of heat conductivity of cooled semi-vacuum (water vapor + air)

I am preparing a classroom demonstration about heat, including a demo of how a satellite loses heat only radiatively, since it's flying through a vacuum. I'd like to make the vacuum-production ...
2
votes
1answer
36 views

What thread to use in tapping a hole for a 2-56 Helicoil insert?

Helicoil from McMaster-Carr 18-8 Stainless Steel Helical Inserts 91732A201 calls out a specific tap to use, but I cannot find out what thread this tap is putting into the hole for the insert. I want ...
0
votes
1answer
39 views

90 degree pivot steering system to allow vehicles to move sideways

Are there any restrictions that would not allow a steering system to cause a vehicle to be able to move sideways - at 90 degrees from the convention direction of travel?
3
votes
1answer
36 views

Can secondary beams be supported to columns occaisionally?

If there are secondary beams running between primary beams, and columns support the primary beams, then is it allowable to have the occasional secondary beam pinned to a column? Otherwise it seems to ...
3
votes
3answers
113 views

Can I use a wooden flat screw head with a washer to mimick a pan head screw?

For example - I am installing a fold up table from Ikea, it needs to hang from the wall, as shown below. It explicitly says to use pan head instead of flat screw heads like shown in the picture, I ...
0
votes
0answers
16 views

Two wire tandem gas metal arc welidng (GMAW-TW)

Please explain how two wire tandem gas metal arc welding (GMAW-TW) process requires less heat input. Appreciated if reference is given.
2
votes
1answer
38 views

How to add radial protrusions to a disc in Autodesk Inventor

First post here, trying to get a little help with Autodesk Inventor. I am trying to make a part that is basically a wheel with little nubs on the end (think of a lego with tabs on the outer ...
1
vote
0answers
16 views

Virtual work method for a disk with axisymmetric distributed and concentrated loads

I'm trying to determine all forces/reactions on a disk with a hole in the center. The disk is loaded with a (known) uniform distributed load from A to C (all around the disk), a concentrated (known) ...
0
votes
0answers
15 views

Gear Ratio and Wheel Diameter [on hold]

I have been told that vehicles with larger wheels are less economical. How is that? Also how is it that Gear Ratio is a function of Wheel Diameter?
2
votes
1answer
73 views

Which is the best extendable pole?

Which of these poles would be straighter and stronger then the others? 1) STEM ( Storable Tubular Extendible Member), a pre-stressed piece of thin metal that could be rolled up like a carpenters ...
0
votes
0answers
18 views

Gears, transmission

Good day, I hope I can express this question of mine properly as a non-native speaker and without the proper knowledge of the terminology in English. I've got a small Stepper motor on which I will ...
1
vote
0answers
20 views

What does 'Analysis Model Value' in NASTRAN optimization mean?

I am new to MSC NASTRAN and PATRAN. I am running a simulation on composite laminate optimization. While creating the design variables for the study, I noticed that there is a parameter called '...

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