Questions tagged [fluid-mechanics]

Questions relating to fluids at rest (fluid statics) or the forces and effects of fluids in motion (fluid dynamics).

Filter by
Sorted by
Tagged with
0
votes
0answers
13 views

Why is a throttling valve isenthalpic whilst a nozzle is not?

From my understanding, Nozzle's and throttling valve are devices which both trade pressure for velocity, so they increase velocity at the expense of having to decrease the pressure. If we examine ...
0
votes
2answers
59 views

Is Bernoulli’s equation applicable for systems with pumps?

Please have patience with me as I have not looked at this sort of theory in many years (I am also very new to StackExchange). A question asks the following: A sloping swimming pool two-thirds full of ...
0
votes
1answer
54 views

How to mix pure CO2 with air so that a bioreactor can be fed with air at 0.1% to 10% CO2?

The situation is we have to prepare a gas mix of air and CO2 which has to be given as input from 0.1% to 10% CO2 of air mix to the aqueous medium in a bioreactor? I'm trying to build a simple and ...
1
vote
4answers
71 views

Balancing suction air flow at different areas on pipe

I have a T-shaped pipe that is connected to a vacuum pump. Along one side, there are 4 areas of 9 holes where air will get sucked in from the surroundings. It's used to pick up some small objects. The ...
2
votes
1answer
64 views

How can I make a vacuum pump to move rocks from one place to another?

I am trying to build a vacuum pump by myself and move rocks from one place to another. After some online search, I came across this video on Youtube. I am trying to build something like this. Can ...
1
vote
1answer
65 views

Is a no-moving-parts air pressure transformer possible?

Is it possible to construct a solid state fluid system (tubing, channels, chambers, nozzles, etc.) that can convert the energy from a low-pressure high-flow-rate air current into a high-pressure low-...
2
votes
0answers
17 views

Book recommendation for hydrodynamics of bubbles, drops, and particles

I am wondering if someone could please recommend to me some references on the topic of hydrodynamics of bubbles, drops, and particles, preferably in the context of complex and bio fluids. I am ...
1
vote
0answers
17 views

Is NPSHr dependant on temperature?

I know that net positive suction head available depends on temperature since viscosity, density and vapour pressure depends on temperature but how about NPSHr? We know that the vapour pressure depends ...
1
vote
2answers
41 views

Can I dismiss wind loads for this solar panel configuration?

I asked this question before in the Physics Stack Exchange, but it was closed because it was considered being about engineering. That is why I am asking it here. I am planning to install some solar ...
1
vote
1answer
36 views

Need help on conservation of momentum (liquid jet) Problem!

I had a quick question regarding this homework problem, I can't seem to understand why they chose to use the conservation of momentum in vertical direction and not the horizontal direction as you ...
1
vote
1answer
26 views

Analytical solution for the 1D convection-diffusion equation

The Ogata and Banks analytical solution of the convection-diffusion equation for a continuous source of infinite duration and a 1D domain: where C [mol/L] is the ...
2
votes
0answers
17 views

Non-Dimensionalizing Navier-Stokes equation to derive the Thin-Film Equation

I want to start with the general Navier-Stokes equation in 3-D: $$ \frac{\partial \vec{u}}{\partial t} + (\vec{u}\cdot\nabla)\vec{u}=-\frac{1}{\rho}\nabla p+\frac{\mu}{\rho}\nabla^2\vec{u}+g\sin{\...
1
vote
0answers
24 views

What is a safe and efficient temperature range for absorption chiller generators?

I've read that the role generators play in the absorption chiller cycle is to concentrate the salt solution so that the evaporator/absorber can maintain a vacuum by constant absorption of vapour ...
0
votes
1answer
29 views

How Do I Calculate the Velocity of the Flow That Is Sucked Into Two Parallel Walls by a Fast Moving Flow?

I'm trying to solve a problem where I calculate the velocity of the setup bellow. Basically I have two very long(basically infinite for calculation purposes) plates, and I have one central jet of gas ...
0
votes
1answer
79 views

In which bucket , should the water fill it up first?

Here , we have two water filters and buckets . Now , we know that as the water falls down , it’s speed increases because of acceleration due to gravity. Let us say I started both the filters and once ...
1
vote
1answer
32 views

Angular Velocity And Flow Rate Relationship Of Turbine

I was designing a turbine to be utilized in order to measure the flow rate of a river system. I can measure the angular velocity of the shaft by utilizing a magnet and hall sensor, however, in order ...
3
votes
3answers
182 views

Given flow rate of an orifice at one pressure, how do I calculate flow rate for a different pressure?

Given an orifice rated 1.8 GPM of water at 90 PSI, how do I calculate the flow rate at 30 PSI and what rating I would need to purchase to achieve 1.8 GPM at 30 PSI? Below added to give some context, ...
1
vote
0answers
17 views

Stokes Number (characteristic length)

I am working with a high speed flow that is non-stokesian, but that isn't the issue. There are correction factors for that. I am attempting to figure out what value to use for the "characteristic ...
0
votes
1answer
39 views

Do throttling devices need valves?

Why is it that a throttling device always has a valve leading to it? If in a closed system loop, a cooled gas exists right before the throttling device, shouldn't the sudden decrease in cross-...
1
vote
1answer
94 views

How does steam in almost vacuum condense at 35 Celsius?

I read about absorption chillers and found out that the water is evaporated/boiled off at the generator. Water boils over at about 3.7 Celsius in the near-vacuum conditions in the generator. Now the ...
1
vote
1answer
38 views

Absorption chillers: can they achieve temperatures below zero Celsius?

If I understand correctly (history shows I probably don't), then the only reason why the absorption chiller evaporators are restricted (I hope that's the right word) to extract just enough heat so the ...
0
votes
1answer
44 views

Which kind of paper has highest absorption speed?

I am experimenting to analyse the liquid wicking(radial) behaviour of various liquids. I have performed initial studies and experiments on household paper towels but they tend to deform and stick to ...
0
votes
2answers
45 views

What are the benefits of reducing valve duration in an engine?

From my understanding this would be beneficial if you've taken a stock engine and put a smaller, more restrictive air intake on it. It would also be done to create more low end torque which shifts the ...
1
vote
0answers
86 views

Will high velocity air directed underneath a half-toroid shaped Coanda saucer by a centrifugal impeller create a lifting force?

I would like to know if a lifting force will be created by the Coanda effect from high velocity air that is directed underneath a half-toroid shaped saucer by a centrifugal impeller. I am seeking an ...
0
votes
0answers
28 views

Symbol for background shear

Can someone please help me with the symbol for background shear? To give you a bit of context, I am referring to background shear as in the following sentence taken from Hussian et al.: Vorticity ...
1
vote
1answer
42 views

Component selection type for fluid-mechanical system

I am creating an enclosure and need to get a water supply through a plastic wall inside to the core device. I imagine this water line will be a flexible tube and will screw on or snap to an adapter on ...
1
vote
0answers
14 views

Imposing/ensuring a constant mass flow rate in turbulent flow simulation

I'm trying to simulate using Finite Elements (non commercial software) the Tube Bundle benchmark problem: http://cfd.mace.manchester.ac.uk/ercoftac/doku.php?id=cases:case078&s[]=tube&s[]=...
0
votes
0answers
43 views

Selecting a water pump for low flow and 1 Bar pressure

I am designing a small automatic drip irrigation system. There will be about 10-15 drippers. Flow through the system will be about 1 l/minute, but this may change if expanding or reducing the system. ...
0
votes
0answers
20 views

Fluid dynamics through tee wye bend

I'm designing a small system where typically a ball valve is used to divert water through a heater when desired. I've noticed the ball valves designed for this situation result in a hard 90 degree ...
2
votes
2answers
59 views

How to use excel spreadsheet formulas to find optimal camshaft profile [closed]

I have a 600cc 4 cylinder Honda engine that my race car team uses. The rules of the race mandate that we install an intake that is substantially smaller than the stock factory intake size to limit ...
0
votes
0answers
19 views

Why is it more convenient to express stress tensor in Material rather than Spatial coordinates?

I was reading chapter introduction about Stress and the author wrote the following about stress tensors: "Since the current configuration of many problems, especially those involving solids, is ...
0
votes
2answers
31 views

Question on fluid flow measurement uncertainty

Say you are trying to measure the liquid flow rate (mass or volume) through a pipe and you want to get the best measurement possible, and you have two flow meters. In one scenario, you put one flow ...
1
vote
2answers
82 views

How to determine the force to empty a syringe containing high-viscosity fluid?

I am trying to determine the force it would take to fully empty a syringe using a long nozzle, that contains a high-viscosity fluid. Specifications I'm using: I'm trying to determine the force ...
0
votes
1answer
41 views

Calculating Flow rate and Water Velocity of a pipeline

Background I am trying to assess the Power output of a Pumped Hydro project based on this website. I have all the required inputs except the flow rate (m3/s). Problem However, this is where I think I'...
0
votes
1answer
70 views

How much water do steam turbines consume per kWh of electricity generated?

I know this depends on some factors, and I can only think of these: the inlet steam's temperature and pressure. If there are more factors then please do tell me. What is the maximum figure in liters ...
0
votes
2answers
122 views

Assessing flow rate from open sea into a container

I'm currently assessing sub sea pumped hydro capabilities, and need to use the flow rate in order to calculate power output. I can calculate the energy storage capacity using E = mgh: $E=mgh = ...
1
vote
1answer
24 views

What is the side way force on a flat membrane place perpendicular to the flow of current on one side, and stagnant water on the other

So basically imagine a plate being placed parallel to the direction of flow of water with water flowing with a certain velocity on one side of the plate and on the other side it is almost stagnant. ...
0
votes
1answer
43 views

Pressurizing Oxygen simply and efficiently

I am an Indian, ravaged by the Covid-19 pandemic in my country. I come from a non engineering background (Physics). I was thinking about the following. If one has an oxygen concentrator, i.e. a device ...
1
vote
0answers
36 views

Nitrogen Flow Problem

If I have a tank of nitrogen gas at 2000 psi (13.79 MPa) and a pipe of 10 mm cross sectional area and 1 meter long how long would it take to fill another, initially empty tank, to 5 L at 1000 psi (6....
0
votes
0answers
18 views

Source-Sink pair with different strength

I know when I have a source-sink pair with equal strength in a uniform flow, I get the rankine oval. Lets say that my source is know +1.25*Q and my sink is -Q, would I still get some sort of "...
-1
votes
1answer
63 views

How to graph a dimensionless ratio as the parameter on an XY graph? [closed]

We conducted an experiment to determine the relationship between the heat transfer coefficient for forced convection over a cylindrical rod due to varying air flow velocities. The relationship that ...
1
vote
1answer
19 views

Calculating final temperature of humid air and cool stone

I'm trying to gauge the efficiency of a night-cooled stone to condense water from the humid air at seashores at noon. I'm assuming the stone is thermally insulated once it's in thermal equilibrium ...
0
votes
2answers
74 views

Pumps' geometric similarity

Given two pumps that are similar : $H_1=70-1.41x10^{-3}Q_1^2$ $H_2=100-1.1x10^{-3}Q_2^2$ Find the geometric scale : $\frac{D1}{D2}= ?$ I am also given maximum efficiency = 1. I tried solving but I got ...
0
votes
0answers
19 views

Side entry mixer sizing

I'm involved in purchasing a set of mixers for a crude oil storage tank. The tank volume is around 98,500 cubic meters. The main purpose of the mixers is base sediment & water control (cleaning). ...
1
vote
1answer
35 views

What is basic knowledge wanted from a bachelor mechanical engineering student before joining? [closed]

At the moment, I just finished my senior school year and in a few months, I will be studying mechanical engineering as bachelor degree. However, I don’t like to waste my time and want to use this time ...
0
votes
1answer
57 views

Boundary layer thickness decreases as fluid velocity increases, so why is the boundary layer thicker in the turbulent region for higher velocities?

I am modelling transitional fluid flow over a flat plate, and investigating the effects of free stream velocity on boundary layer thickness. From what we have been told, increasing free stream ...
1
vote
1answer
43 views

Why is the head loss in submerged pipe is 0

Looking at this question : Point C head loss is 0 according to the author Bottom right Can’t understand why , any good explanation for this claim ? Look at page 33 at the top
1
vote
0answers
26 views

HVAC Condensor Liquid Level/Ratio Estimate

Let's say I have a simple condenser inside of a HVAC system with 1 point of entry(Super-heated Vapour) and 1 point of exit(Saturated Liquid) for my refrigerant r134a. A pipe passes through it with ...
1
vote
1answer
74 views

Venturi Duct flow

When water flows through the converging side of a Venturi, why is it that the total head (experimental and calculated) is not constant? Could it be due to losses? Also, why was it that a lot more ...
1
vote
3answers
49 views

measurement accuracy in %

I am running a simulation of fluid flow and then doing an actual physical experiment to confirm the results of the simulation. My simulated results show a value of 0.529 m/s and my experiment show a ...

1
2 3 4 5
18