In a unit of two shell-and-tube heat exchangers(pre heater & evaporator), how I can model step change in flow rate in case of dynamic simulation?

What is the characteristic length to determine the Reynolds number for the scattered turbulent fluid flow?

Dear all, I just saw this example in FB on the difference between laminar flow and turbulent flow. The flow from a pipe hits the sink and scattered. The flow from the pipe is characterized as...

02 March 2021 1,999 5 View

Why almost every element would be metallized in sufficiently high pressure and low temperature?

(This statement is from wikipedia, BTW). What is so special about metallic bond that is limiting high-P low-T state of a matter (as long as individual atoms exist, not white dwarf of neutron star...

02 March 2021 3,309 2 View

What are the countries most affected by extreme rainfall as a result of climate change?

Increased heat, drought and insect outbreaks, all associated to climate change, have increased wildfires. Decreasing water supplies, declined agricultural yields, health impacts in cities owing to...

01 March 2021 7,168 9 View

Issues with Permeabilization during Flow Cytometry?

Hello Everyone. Currently I am working to characterize macrophages in the myocardium after ischemia-reperfusion injury in rats. Due to the low total cell number isolated from rat hearts I can...

01 March 2021 3,867 3 View

What is recommended for solid domain in ANSYS FLUENT?

Should I mesh the solid domain ? or should I use wall thickness? or Shell conduction? for Heat Transfer between two fluids of a Heat Exchanger. what is recommended?

01 March 2021 9,785 3 View

Heat exchanger with liquid Nitrogen as coolant?

I want to cool Natural Gas from 195 Kelvin to 138 Klevin in a heat exchanger by using liquid nitrogen as the coolant medium. When entering the heat exchanger, the liquid nitrogen will have a...

01 March 2021 6,450 5 View

How can i resolve the "final solutuin is not converged" error in Comsol for my heat transfer simulation??

I have been trying to simulate heat transfer problem in Comsol 5.5 for long time but it always throw an error stating: "Failed to find a solution. Maximum number of Newton iterations...

28 February 2021 8,626 3 View

PUC19 as a transfer plasmid for lentiviral delivery?

Hello, Is it possible to use pUC19 as a transfer vector to be packed in using the second generation viral particles packaging system( pMD2.G; psPAX2 plasmids)? As far as I understand it there is...

28 February 2021 4,868 2 View

Exit velocity of natural gas from pressurized tank?

Hi Guys. I'm a mechanical engineer and have a bit trouble, would be very glad if you could help me with my questions. I have a pressurized tank which contains Natural Gas at 200 Bar and 293...

26 February 2021 6,253 3 View

Why do the air flow results vary totally when adding scalar in CFD ?

Dear All, We are using Autodesk cfd to calculate the air flow in a single sided naturally ventilated room, where air flow depends only on buoyancy due to temperature difference between inside and...

25 February 2021 9,602 4 View

Javad Ackbari

The cold side mass flow rate (or process stream) varies with time. Steam at evaporator outlet should be reached to a prescribed amount to enter the next unit. I don't have any function for heat transfer coefficient because this unit is in design phase. I want to know how long steam takes to reach prescribed amount?

Shiuh-Hwa Shyu

Use a CFD code with a small time interval can serve your purpose.