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Questions related from Paresh Gujarati
Currently I have prepared a circuit which gives me constant current source of 10 micro ampere. 2 Volt DC source and 200 k Ohm resistor in series. What if the output volt of DC power supply...
06 June 2016 7,207 4 View
Currently FVM is most popular method to solve fluid flow involving heat transfer problems and related physics. On the other hand, FEM is mostly suitable and popular for structural analysis.
07 July 2015 7,592 0 View
What is the meaning of numerical diffusion? How to reduce or avoid it?
05 May 2015 7,930 3 View
Currently I am using Gauss Siedel Iterative method to solve CFD equations. I am facing instability problem i.e. iterations keep on increasing without change in rms value for a given variable such...
12 December 2014 8,988 14 View
I normally read the terms viz. charged pressure and mean pressure while browsing cryocoolers research papers. I do not understand what is the actual difference between them? How do both differ...
09 September 2014 8,343 4 View
I am doing numerical modeling of pulse tube cryocooler (with oscillating pressure and temperature) with finite volume method. I have successfully implemented it with implicit scheme by use of...
08 August 2014 4,251 34 View
I will be using a needle valve for my practical setup of project work. It is based on pulse tube cryocooler. I need to calculate the coefficient of discharge for needle valve for report purpose....
05 May 2014 7,305 7 View
Currently I am doing numerical analysis of pulse tube cryocooler and dealing with various parameters keeping others constant. I am saving data of each set in my computer date wise. I want to know...
05 May 2014 8,305 1 View
I am currently working on 1-D numerical simulation of pulse tube refrigerator. The governing equations are given in attachment. I have plotted results showing mass flow rate over the cycle (mass...
03 March 2014 1,056 0 View
I am currently doing numerical analysis of GM type Pulse Tube Cryocooler. Governing equations are a system of boundary value problems and one need to use shooting method to solve it (as per one...
03 March 2014 4,883 1 View
I am using Jacobi iterative method to solve sets of linear equations derived by discretization of governing equations of fluid. First I implemented First order Upwind method which works quite well...
02 February 2014 8,841 2 View
I am doing experimental research work on Pulse Tube Cryocooler. I need to find out what the coefficient of discharge is through a rotary valve which is used to control the frequency of operation...
02 February 2014 2,908 1 View
I am working in cryocooler modeling and want to know the heat transfer coefficient calculation for low frequency (1 to 5 Hz) cryocoolers like GM cooler or GM type pulse tube cryocooler having...
12 December 2013 6,003 0 View
In pulse tube crycooler, during CFD analysis of it, we must enter pressure oscillation as input. The pressure oscillation repeats itself after a cycle is over. How to write UDF for pressure inlet...
11 November 2013 6,766 7 View
I am doing numerical analysis of GM type pulse tube cryocooler. Before doing transient analysis, I want to do steady state analysis to get cooling power. When the PTC system reaches to steady...
11 November 2013 8,955 2 View
I need to use temperature dependent specific heat of stainless steel and lead balls in numerical analysis. Can anyone give me charts, equations or any source from which I can get the temperature...
09 September 2013 5,266 6 View
I want to use shear strength data of SS 304 for one application. How do we know how much strength any material possess in shear? How one can get the shear strength data of any material?
09 September 2013 3,060 6 View
In one of the application, I need to use rotary valve, which contains stator made up of stainless steel and rotor with teflon material. When the rotary valve is connected with electric motor,...
09 September 2013 4,133 4 View
Why does helium behaves almost as an ideal gas at 50 K and above temperature at moderate pressure? What is the factor that decides 50 K temperature limit for ideal gas behavior?
09 September 2013 6,637 7 View
In pulse tube cryocooler analysis, a quantity named cycle averaged pressure drop, cycle averaged mass flow comes into the picture. My doubt is it average means RMS average or simple average?...
08 August 2013 4,152 1 View
I am working on GM type pulse tube cryocooler and I have found that pressure ratio decreases along with the temperature reduction. I do not know what is the reason. As the temperatures goes down...
08 August 2013 3,576 3 View
I would like to know the meaning of d2P/dx2 = 0 which is the pressure boundary condition for oscillating machine i.e. GM Type pulse tube cryocooler. I want to know, how to deal with these pressure...
08 August 2013 3,994 2 View
I want to use the thermo-physical properties (such as specific heat, density) of lead shots (balls) as function of temperature from 4 Kelvin to 310 K. Can anyone provide me the source or link...
07 July 2013 1,319 2 View
We need to find out the coefficient of discharge for oscillating helium-4 flow for GM type pulse tube cryocooler. We want to measure this oscillating velocity so that we can measure actual flow...
07 July 2013 9,385 5 View
How can one determine the coefficient of discharge for oscillating helium flow from 22 bar to 8 bar? The oscillation is produced by a rotary valve which generates the sinusoidal pressure waveform...
07 July 2013 4,825 7 View
I am doing 1-D numerical modeling of the pulse tube cryocooler. I am referring one paper which says that pressure boundary conditions at left end of regenerator (from where oscillating helium gas...
07 July 2013 5,469 2 View
What are the different situations in which one is required to use different upwind schemes? We know first order upwind, second order upwind and QUICK as some advection schemes. I want to know...
07 July 2013 7,791 8 View
