# All Questions

6,912 questions
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### 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 ...
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?
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### 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....
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, ...
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 ...
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 ...
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### 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 ...
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### 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. ...
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 ...
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 ...
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 ...
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 ...
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 ...
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### 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 ...
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### 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 ...
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 ...
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 ...
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### 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 ...
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### 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?
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### 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 ...
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 ...
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### 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.
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### 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 ...
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### 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) ...
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### 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?
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### 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 ...