Questions tagged [fluid]
The fluid tag has no usage guidance.
42
questions
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2answers
46 views
How is the flow work PV?
I am reading thermodynamivs from cengel and boles.I am currently studying flow work.Following image contains text of the book.
(https://i.stack.imgur.com/eCGXR.png)
The workdone is calculated by ...
0
votes
1answer
41 views
How can I connect F=ma to Drag=1/2*Cd*(rho)*V^2*A?
I previously posted a different question that was very vague. I have kept working on the problem, and now I have a different question. Please let me know if I should have just added it to the old ...
0
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1answer
15 views
Choosing a pump to inject liquid into a pressurised water pipe
I'm interested in using a pump to inject liquid into a mains water pipe (3-6 bar pressure)
I don't know what pump to use as they all seem too big for the task they are carrying out. I want to use a ...
-1
votes
1answer
32 views
1
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2answers
39 views
Measuring viscosity with tools other than viscometer
I would like to measure viscosity, but do not have access to a viscometer. If possible, I would like to avoid having to purchase one. I have access to many other flow measuring devices, including ...
2
votes
1answer
42 views
Buckingham-Pi Dimensional Analysis when there is a non-dimensional parameter: How is it accounted for?
I am in the process of completing a design project for my fluids course in which Buckingham-Pi /Dimensional Analysis is needed to find the optimal parameters needed to achieve a rotational rate of 120 ...
0
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1answer
39 views
Frictionless Flow
Suppose we have a water reservoir at some elevation say z and the flow is frictionless then by Bernoulli's equation we have the exit velocity (2gz)^0.5 . This means that the static pressure in the ...
0
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1answer
43 views
Water & plumbing pipes vs gravity or air pressure
I'm sure there is a simple answer here, so i apologize in advance for the unchallanging & low level question, but here it is:
Why does the water at water oulets, through out a building, stop ...
0
votes
1answer
39 views
What are fluids or “goos” called, that increase friction?
I have a shaft inside a bushing, the shaft has a gear on one end that is supposed to provide resistance to other gears it is driven with.
I'm having a hard time finding the correct term for the sort ...
0
votes
1answer
23 views
Determine Cp of an oil from density and temperature?
I suspect I know the answer to this, but hoping someone may know something I don't here.
Is there a way I can determine the specific heat capacity at constant pressure (Cp) of an oil if I know the ...
0
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0answers
47 views
How does this transformation actually happen?
I cant exactly give you the complete relevant details of the variables but assume the following (bold means vector):
B(x) ~ $\frac{1}{8\pi}*(\nabla\frac{1}{r})\times\int \mathbf X'\times \mathbf \...
0
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0answers
15 views
Finding flow rate contribution from difference in temperature
Currently I am working on a DTS(Distributed Temperature Sensor)data and PLT data and I need to figure out a relationship between temperature and fluid flow-rates in various locations (depths) of the ...
0
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0answers
23 views
Method of Hydraulic Resistances (Crane TP 410), how accurate is it really?
A bit vague but a question for you working engineers out there.
For a couple of years now I've been designing fluid systems, mostly using Crane's TP 410 as the guiding resource for pressure drop ...
1
vote
1answer
22 views
Volumetric flow in a pipe from velocity
I think I'm missing something important here.
For a fluid with a velocity $u$ in a pipe with cross section area $S$, the volumetric flow rate is equal to:
$$Q_v = uS$$
If we now consider vectors, ...
0
votes
1answer
50 views
the angle of water surface in a moving car
in this picture, there is a container of water and it is moving on the slope.
we want the acceleration of the container while the angle of water surface is parallel to the slope.
so the book says the ...
2
votes
0answers
29 views
Fluid for mechanical lubrication and hydraulic connection to plastic/rubber parts
I have a piston made of anodized aluminium and stainless steel with nitrile seals which I need to connect hydraulically to our system which mainly consists of silicone rubber with polycarb and acrylic ...
0
votes
1answer
69 views
Fluid dynamics of a valve
I am new to fluid mechanics and am trying to understand the fluid mechanics of a simple valve.
Let's assume we have a simple tube, which is supplied with a constant stream of liquid using a pump.
At ...
0
votes
2answers
51 views
What pressure to take in surface tension question?
Pressure inside a water droplet is $0.32 N/cm^2$ if surface tension of liquid is $0.095 N/m$. We have to find the radius of the bubble
since it's a water droplet the formula used is $$P_i-P_o=\frac{...
0
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1answer
54 views
How to solve analytically this equation? [closed]
I need to solve the next equation and to find $x_1$:
$$\dfrac{d(x_0x_1)}{dz}=-\beta\dfrac{dx_0}{dz}\dfrac{1}{r-z(r-1)}$$
where $x_0$, $x_1$, $z$ are variables, and $r$, $\beta$ are constants.
At ...
0
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2answers
40 views
Will a fan that is composed of several fans fixed inside rotating tube work?
I want to design a custom 3D printed fan that would be made of several axial fans that would be connected (fixed) to their cylindrical casing. I am planning to rotate the whole assembly (the cylinder ...
1
vote
0answers
26 views
Is RotCFD or Ansys Fluent better to capture the wake pattern far downstream of a flow in the case of a rotating blade?
My main constraint is that the wake pattern to be worked on is far downstream.
Which one will give me more accurate results?
Will these two work well for the far wake at all?
1
vote
0answers
37 views
Relation between airespeed and pushing force
I'd like to know how can I estimate the maximum speed that can be achieved by a
"portion of wind" accelerated upward from rest on the surface of
a place by pushing forces.
So far I've thinking in the ...
1
vote
0answers
20 views
Determination of delivery pressure from pump in my Parts Washer
We want to know how can we determine the pressure of the liquid at the delivery end of the pump. We have a centrifugal pump and a 2" pipeline at the delivery end. Pump delivery performance as per ...
1
vote
2answers
63 views
I want to know the water flow rate from a certain height knowing the flow rate at near the ground level
I used a bucket to find out that at 1 feet high (a garden faucet) the flow rate from an half inch pipe is 1 gallon in 26 seconds
At 3 feet high (face basin) the flow rate is 1 gallon in 30 seconds
at ...
0
votes
1answer
61 views
shape of cylinder in the fluid mechanics
in the following picture, we should find the viscosity of fluid and we have to have the Area surface of cylinder that is in touch with the fluid.
the area surface depends on the bottom of the shape.
...
0
votes
3answers
110 views
Calculating diesel volume in a horizontally-cylindrical tank
This is about several diesel tanks that need to be monitored in terms of diesel volume.
I want to measure and monitor the volume of Diesel liquid inside horizontally cylindrical tanks with standard ...
4
votes
1answer
635 views
How to calculate the volume capacity flow rate of a vertical pipe?
There is a rain pipe in a house. I want to know how many cubic meter rain water can flows through the given pipe in a minute. I need to know the maximum capacity of the pipe. In other words: How many ...
2
votes
1answer
54 views
Designing for a specific flowrate
I have a simple, practical engineering question.
I'm trying to design a hot water circulation system with a constant flow rate of 1.3 L/min. I'm having trouble finding any pumps that will do the job ...
3
votes
1answer
753 views
Losses through holes drilled in a pipe
I asked a previous question about pipe t-junctions with pipes of varying diameters, and it got me wondering...
How are losses handled and calculated in pipes with holes drilled directly into them? ...
11
votes
4answers
2k views
Would an object at the bottom of the sea still experience buoyancy? [closed]
So I understand that buoyancy happens because the fluid exerts larger amounts of pressure from beneath an object compared to above, like in this picture
So my question is, what if the object is ...
2
votes
3answers
1k views
Can Siphoned water travel a distance of 2500 ft with a height difference of 10 ft?
I have access to lake water. My land is situated in the back of this lake. In summer, water in the lake shrinks to a distance of about 2000 to 2350 ft away from my land. My land is 10 feet above the ...
4
votes
1answer
116 views
Methane Gas Density in Adiabatic Compressible Flow
Hi.. The question above is one of the tutorial question from fluid mechanics textbook. In the textbook solution for this question, the density of the methane gas stream at downstream was computed with ...
0
votes
1answer
37 views
Variational Problem of slow steady flow of viscuous fluid in 2D
I have a Problem with a transformation.
The energy function is the following:
$$I(u_1,u_2,P)=\int_R [\frac{\mu}{2}(u_{i,j} + u_{j,i}) u_{i,j}-Pu_{i,i} dx_1 dx_2 - \int_R f_i u_i dx_1dx_2 +\int _S ...
0
votes
1answer
304 views
O-Ring Selection for a round rectangle groove
I'm designing a water proof case for a power bank to be used in an occasional underwater condition. The input and out put port components already have a gasket or sealing ring. Now to close the case I ...
1
vote
0answers
14 views
Help finding a thixotropic suspension with specific properties
I currently doing research on 3d printing on circuit boards. The technique we are using is to put a conductive material, I.e ceramics/metal in a gel/polymer, to print the suspension and then when is ...
2
votes
0answers
159 views
Fluid Statics Problem
I have been attempting this question for a while now. Could anyone give me a hand?
The question and the work I have done so far is below. My final "answer" is
P (force required to keep the gate ...
1
vote
0answers
30 views
Can a cellulose sponge be used as an actuator to shut off flow of water temporarily?
In non-recirculating hydroponic systems, we want to fill containers with nutrient rich water let's say up to an inch, let the plants take up the water , give the plants some air time for a few hours, ...
1
vote
3answers
92 views
Calculating the radius of a hole for a desired outflow rate
I am tasked with finding the radius of a hole at the bottom of a tank to obtain the desired outflow rate when the tank is full.
The tank is a cylinder with dimensions Height: 4.8m and Radius: 1.79m. ...
0
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2answers
72 views
Velocity of Fluid Flow
If a water pipe has a large diameter at the start and a small diameter at the end what part of the pipe would the water flow faster?
0
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1answer
467 views
How to calculate flow rate of viscous fluids through a funnel-shaped needle?
How would you determine the flow rate of a liquid that flows through a narrow microneedle channel and then through the opening of a funnel, i.e. pouring liquid through the other end of a funnel?
I'...
0
votes
1answer
71 views
Direction of rotation of turbulent eddies in channel flow
Suppose we have a isotropic homogeneous turbulent channel flow. We know that this flow is associated with many swirling eddies of different length and time scales. I need to know the direction of ...
1
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0answers
216 views
Buckingham Pi theorem, repeating variables
I'm having trouble understanding the 4th step to the Buckingham Pi theorem.
My variables are:
weight ($\text{N}$) : $\text{MLT}^{-2}$
h ($\text{m}$): $\text{L}$
Diameter ($\text{m}$): $\text{L}$
...
