49 Questions 82 Answers 0 Followers
Questions related from Deewakar Sharma
Hello all, I am trying to study a very simple case of bubble rise ( air in water) using Phase field method in COMSOL. However, again and again I get this error " fFailed to find consistent...
11 November 2019 2,105 2 View
Hello all, I would like to some help regarding the following problem. I have some data based on some numerical experiments and would like to make a empirical relation out of that. While there...
10 October 2018 6,613 1 View
May someone help in understanding the difference between phase-field method and level-set method? Thank You
01 January 2018 3,651 5 View
Hello all, I am trying to simulate spinoidal decomposition using phase-field method. Most of the literature I could have given equations in dimensionless form. However, I intend to solve them in...
11 November 2017 4,237 4 View
Hello all, I am confused about the following fact. Does minimization of free energy always mean that entropy is maximized? are they always complimentary to each other or in certain conditions? I...
05 May 2017 1,663 5 View
Hello all, I am looking for an analytical expression of temperature of the bulk fluid due to piston effect (in near critical fluids) Can someone help in locating appropriate text. Thanks
04 April 2017 8,548 5 View
Hello all, I am looking for Volume of Fluid model for compressible flows. If I am not wrong, then VOF is single fluid model. May some one suggest some relevant literature for two phase...
06 June 2016 597 5 View
Hello all, The question may sound very naive and subjective to problem being dealt, but I would like to know why do parametric instabilities occur in general? May someone explain Thanks
06 June 2016 8,489 0 View
Hello all, I have some doubt regarding shape Gibbs function (or any thermodynamic potential) w.r.t volume (or any Intensive property). Why does near the critical point it has two minima? May...
03 March 2016 3,126 2 View
Hello all, The question may seem naive , but I would like to seek some clarification reg the following: a. What is difference between statistical and non statistical thermodynamics? Is non...
03 March 2016 6,441 3 View
Hello all, May some one explain in simple way the difference between numerical diffusion and numerical dispersion? Most of the literature I could find used Finite Difference Method to describe....
12 December 2015 2,430 11 View
Hello all, I have come across the following relation at many places reg. water hammer and acoustic in compressible flow i.e Pressure = density x fluid velocity x sound speed in fluid. I am...
12 December 2015 8,071 4 View
Hello all, I am trying to study fluid in a container subjected to angular vibration using my own code. I am not able to find any test case to validate the results. As per my results, I get...
11 November 2015 5,758 2 View
Hello all, I was willing to know how utility of Richard Extrapolation in CFD. I know it can be used for estimation of order of scheme by running numerical simulation for 3 different grid...
06 June 2015 5,488 6 View
Hello all, I am trying to write 2D code for flow between parallel plates using FVM and SIMPLE algorithm in staggered grid. I am having a serious issues with boundary conditions. I am using cell...
04 April 2015 2,892 12 View
What exactly is back pressure? In usual flow we have a Resistance to flow due to viscous effects and in addition due to bends etc we have some pressure drop due to bends, protrusions etc. which...
11 November 2014 3,003 1 View
Hello all,I would like to seek some clarification regarding smooth and rough pipes and subsequently friction factor relations. As per the moody diagram we have, that in laminar regime friction...
11 November 2014 6,399 16 View
Hi all. I have just begun with the field of instability and going through texts of Francois Charru. While going through Rayleigh Benard thermal instability (where, to best of what I have...
11 November 2014 4,958 5 View
Can someone explain how in the figure attached cascading helps to increase pressure capability? I agree in a single stage (comprising of small channel and large channel passage) we have higher...
11 November 2014 4,657 0 View
Dear all, I came across the figure attached from a text in CFD using FVM. As per the text, the final convergence rate decreases with mesh size. However, I am unable to understand the information...
11 November 2014 992 13 View
Hi, I have just begun to work in the area of microscale heat transfer with two phase flow. I am looking for some good text book which may be complete (or atleast nearly complete) regarding this...
10 October 2014 5,154 5 View
I am new to the work related to hydrodynamic stability. May someone briefly explain the technological significance of this aspect. I mean mostly I come across is how is transition taking place,...
09 September 2014 2,545 13 View
I recently came across a text wherein it was described that for continuum assumption, one of the condition is thermodynamic equilibrium. For thermodynamic equilibrium, high frequency of inter...
08 August 2014 1,736 4 View
I am willing to write my own code to solve NVS for a conjugate heat transfer problem. I have been trying this for a long time but am unable to get it right. I tried to Google but there are no...
06 June 2014 8,081 2 View
I have some confusion regarding the effect of axial conduction at micro-scale heat transfer in micro-channels. Consider a conjugate heat transfer problem wherein micro channels are used for...
06 June 2014 2,418 10 View
We know from Newton’s law of cooling that heat transfer coefficient, h, is h.A(Tw-Ta)=heat transfer, where Tw and Ta are wall and ambient temperature respectively. My concern is whether this h is...
05 May 2014 8,658 16 View
I am doing analysis using FLUENT wherein two fluid streams mix together as follows. In a straight channel there is another inlet at the midway where the second stream of fluid enters (same fluid)...
03 March 2014 1,039 8 View
I am just new to writing own code to my problem. Initially I am trying with simple cases like flow in rectangular duct etc. I am stuck and having issues with following two aspects: 1. While...
03 March 2014 9,069 8 View
I have done a full factorial experiment (using 3 factors) and three center points. The experiment was repeated thrice at main points, overall producing 27 design points. Now analyzing the data, I...
03 March 2014 5,001 10 View
I am confused regarding some basic relations and their approaches in basic fluid mechanics. I tried to look at these in text but couldn't find appropriate answer. If someone may kindly guide me in...
12 December 2013 357 5 View
When molecules of fluid collide with wall of the pipe (or duct through which it is flowing) then I understand that it undergoes elastic collision and rebounds back. However, when there are large...
12 December 2013 386 7 View
I am working in area of micro scale heat transfer but there is one question which has puzzled me for long. I have read in several papers that beyond this limits continuum theory is obeyed...
12 December 2013 1,346 5 View
In fluent there are several options for pressure, static dynamic, total. May any one suggest which one to consider if I am looking for pressure drop for flow in a pipe. I initially went with...
10 October 2013 9,828 8 View
I am trying to write a UDF that executes at the end of convergence to calculate average wall temperature along the length for flow in ducts. For example, consider a rectangular duct, wherein a...
10 October 2013 3,194 8 View
I just came across Total Variation Diminishing schemes, where it has been mentioned that for the scheme to be non-oscillating, the following criteria should be followed: - the scheme should be...
10 October 2013 2,987 1 View
I would like to clarify what is the static pressure in pipe flow? If I am not wrong then the static pressure is usually defined as pressure of fluid at rest and dynamic due to its velocity or in...
10 October 2013 6,407 10 View
Consider a duct of rectangular cross-section in x-y plane with a flow along z direction. Let the length of pipe be L. Assuming that at half length there is an opening or hole from where fluid...
10 October 2013 5,099 15 View
This question may seem to be very trivial but I need further clarification. As we know for flow in ducts, we define fully developed hydrodynamic boundary layer when it stops showing any variation...
09 September 2013 5,694 14 View
While reading a text in a book I cam across the following statement. Maybe someone can explain it in simple terms: " Mixing length models in Boussinesq Approximation need modifications to damp the...
09 September 2013 6,179 13 View
I came across a text in Numerical Heat Tranfer by SV Patanakar that if we know the pressure field we don’t need to incorporate staggered grid arrangement. My question is: Don’t we require...
09 September 2013 2,133 10 View
I recently came across a text in a book in which it was mentioned that viscosity changes with thermodynamic state of fluid. Can some one explain what is meant by Thermodynamic state of fluid?
08 August 2013 9,080 11 View
Can someone explain the difference between vortex and eddies? I came across a text where it was mentioned that once fluid flows an obstacle, eddies are formed. Does that mean when there is no...
08 August 2013 1,704 32 View
I have come across the terms streakline, pathline in fluid mechanics in my UG course but have never been able to get their real applications. If someone may kindly shed some light on this. Also,...
08 August 2013 7,606 11 View
Can't we have 2D turbulent flow?
08 August 2013 2,896 20 View
I recently appeared in an interview where a few questions were asked regarding numerical instabilities. I was asked the following, though I tried but couldn't convince. Can someone help in this...
08 August 2013 7,681 4 View
There are different methods for design of experiments (as per my knowledge). These include Full factorial, fractional factorial, Taguchi and lastly response surface in which there are CCD and Box...
05 May 2012 9,142 5 View
Hello all, I am looking for IVC-SEP package ( Hytoft G. and R. Gani, 1996) to download. May anyone recommend where to get that. I tried looking on web but no success. I am not sure though, but I...
01 January 1970 5,270 0 View
Hello all, I have a very naive question and would like to seek some answers. In case of satellites or any part of rocket that goes into space, to my understanding it surely has some metallic...
01 January 1970 8,755 29 View
Hello all, I am looking for applications or systems where two phases, wherein one is Newtonian while other is non-Newtonian of both are non-Newtonian are involved. Some initial search do gives...
01 January 1970 6,860 7 View
