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Questions tagged [multiphase-flow]

18 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 But this is now considered an outdated practice.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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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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13
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1 answer

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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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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What is Drift flux in two phase flow (Fluid Mechanics)?

I recently started learning about two phase flows. While studying I came across relative velocity, drift velocity and drift flux. I understand the first two terms, but I don't understand the concept of drift flux. It is easy to understand the…
Krishna Sai Kaligotla
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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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Two phase flow in T-junction

I have some hydrostatic/dynamic problem, maybe not that hard, but I am not able to prove it analytically. Here is the setup: Lets assume that there is full water reservoir (details on the picture below) with valve/seal at the end of the pipe (point…
Dulek
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Why does a compressed gas duster get cold?

I have a compressed gas duster with difluoroethane as the gas. When I shake the bottle, I feel sloshing, so I assume that it is a vapor liquid mixture inside. When I expel the gas, the can gets cold to the touch. I thought that liquid vapor mixtures…
nwsteg
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Different pump flow behaviour in common circuit?

I want to evaluate a system of closed circuit. Two hot water chillers are serving two different areas and have different capacities but their hot water source is common due to which we have combined the two pumps circuits at one point to make a…
Muhammad Abid Moten
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1 answer

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} =…
STOI
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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…
casualguitar
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