Questions tagged [multiphase-flow]
14 questions
20
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1 answer
Sizing a pressure safety valve for two-phase flow
I understand that valves in two-phase vapour / liquid were sometimes sized by considering the required vapour and liquid flow rates separately, and then adding the results together. But this is now considered an outdated practice.
I have also heard…
SecondVector
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14
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Estimating whether the flow through a valve or nozzle cavitates
My understanding is that cavitation occurs in the flow of a liquid when the static pressure drops below the vapor pressure, even intermittently. So even if the time-averaged static pressure (what you might measure) is above the vapor pressure, the…
Ben Trettel
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13
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2 answers
How do the bubble oscillations in two-phase flows affect the dissipation rate of turbulent kinetic energy?
I am investigating the effects of bubble oscillations (calculated using the Rayleigh-Plesset equation for bubble dynamics) on the turbulence in two-phase flows. Since I am using cryogenic fluids, the thermal effects also play a role. I am trying to…
Karthik Venkatesh
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6
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1 answer
Multiphase Flow - Energy Coupling Parameter
I have a general question regarding energy coupling in multi phase flow. My question comes is based on the text from this…
MathsIsHard
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4
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1 answer
Modelling gas desorption from a still solution (e.g. a beer)
The common way to model or estimate gas (e.g. CO2) desorption rate from a liquid solution is by using an equation similar to this one
$J_{CO_2} = -k_L a(H·C^G_{CO_2} - C^L_{CO_2})$
where $J_{CO_2}$ is the molar (or mass) flowrate, $k_L$ is the mass…
Toulousain
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2 answers
What causes water to always drip from an electric furnace when its turned on?
I made an electric furnace as a university project. It can heat up air inside up to 1000 degrees Celsius. It's not fully sealed so some air can escape from small gaps. Not sure if this would cause a problem or not later on, but water always drips a…
Bramble
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Sizing a flash tank
I have to size a vertical flash tank that is located on the blowdown line of a steam generator.
General data:
Steam generator pressure: 15 bars
Blowdown flow rate: 1 t/h of water at 198°C
Pressure in the flash tank: 1.1 bar
% of flash steam forming…
Snite
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1
vote
1 answer
Valve/Filter allowing through gas only, no liquid
I need to devise a way to ensure only NG passes through a pipe, and no condensates or other liquids. It is ok to shut down the pipeline if liquids would be detected. The dimensions involved are small and space limited.
Is there a valve which shuts…
Romeoman
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Holzapfel-Gasser-Ogden (HGO) model
Can Holzapfel-Gasser-Ogden (HGO) model be applied to solid porous materials such as rocks, concrete and etc. as well? If yes, would you please introduce a reference.
If not, is there any modified version of Holzapfel-Gasser-Ogden (HGO) that can be…
AMGEO
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Optics: imaging a plane of a water spray/jet
I'm trying to think through a new experimental set-up, involving a sheet of water being shot up over a step structure. The water sheet will be about 5" wide, and the camera will be positioned orthogonally to the flow direction. I'd like to take some…
bonker
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How to model a condenser (heat exchanger) where both streams are two fluid mixtures?
As mentioned I would like to model a heat exchanger (using Python). In this case, the condenser/hx streams are both a mixture of O2 and N2
These are known for both streams:
Inlet temperature
Inlet flowrate (moles)
Inlet composition (fraction of…
0
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1 answer
How to infer from the volume fraction function whether a flow is transient or steady?
Hello dear engineering community.
I have a specific question about multiphase flows. I was wondering if anybody could help me with it, please.
Assume, I have a one dimensional water-air flow. Air is the dispersed phase. Let's say, it's a vertical…
Ivan Nepomnyashchikh
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1 answer
Determination of solid bed fluidisation
How would one determine if a fluidised bed (with liquid flow) is determined to be a stable fluidised bed, which subsequently doesn't form a plug or bed at the top of a column (bounded by frits), when under pressure?
Beerhunter
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-1
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Line to neutral voltage in three-phase power systems
I have the book "Power system analysis and design" by Sarma.
In his intro to balanced LN voltages, in chapter 2 p62 he states:
$$V_{LL} = \sqrt{3} V_{LN} \angle30º$$
but later in the chapter, p70, he states for balanced LN voltages:
$$ V_{LL} =…
RSM
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