117 Questions 180 Answers 0 Followers
Questions related from Hakeem Niyas
In the first lecture of heat transfer course, generally it is told that with Thermodynamics, it is not possible to get the heat transfer rate of a process. But in steady flow energy equation (time...
03 March 2020 1,284 6 View
It can be understood by intuition that gases can't be compressed at constant pressure or constant volume. But what is the thermodynamic reason behind it?
03 March 2020 2,902 2 View
As insulation materials are generally used in the pre melting or much safer temperatures, I am finding difficulty in getting data such as latent heat of fusion of any insulation materials. Can...
07 July 2019 8,340 7 View
Our institute is planning to subscribe/buy hard copy versions of renowned magazines related to Energy sector (especially Renewable Energy). Could you please name some of them.
01 January 2019 9,425 5 View
It's a well know fact that the vector integrals are generalized forms of general integrals, such as 1 - Line Integral is a generalized form of Simple/Single Integral 2 - Surface Integral is a...
12 December 2018 907 29 View
Renewable Energy has a greater scope in research and job opportunities now and it will continue in the future also. Mathematical modeling of the renewable energy systems is highly important to...
11 November 2018 7,500 6 View
I know how to plot a 2D real vector. Let's say I have a vector 'a' represented in a row matrix, a = [1 1]. I can plot it in xy plane and I will be getting a line having the equation...
10 October 2018 5,450 7 View
One principle given in Thermodynamics, Cengel is "The steady flow compression or expansion work is directly proportional to the specific volume of the fluid. Therefore, the specific volume of the...
10 October 2018 5,409 4 View
Can anybody share any resources related to Viscosity of molten Potassium Hydroxide (KOH)?
07 July 2018 5,220 5 View
Can you please differentiate the both using some practical or numerical examples?
05 May 2018 8,114 7 View
The concept of Entropy is generally difficult to understand. So how can it be explained in a very easy manner so that students can get a good clarity about the topic?
04 April 2018 3,096 5 View
I have chosen SS316 as the tubing material for my application, wherein high temperature corrosive fluid is to be passed the tube. Can anybody suggest me a better alternative for SS316? The...
03 March 2018 1,563 5 View
Can thermodynamic modeling be called as a more idealistic and preliminary stage than the thermal modeling? Though assumptions exist in both the modeling, what exactly distinguishes the both?
03 March 2018 3,322 7 View
I would like to know the reason behind the naming 'Reaction' for Reaction Turbines. I am able to convince for the other name 'Pressure Turbine' as the work output is due to the reduction of...
03 March 2018 5,643 5 View
In a 2 parts paper, how to cite one of the parts in the other one?
06 June 2016 3,372 3 View
What are the roles / responsibilities of Editor-In-Chief, Editors, Guest Editors, Editorial Advisoy Board of a peer reviewed journal?
05 May 2016 9,129 0 View
I got an error "AVI files can only be generated if Windows is used" while trying to export an animation from a Linux/Unix computer. Is there any workaround for this?
02 February 2015 5,481 4 View
I have a finned heat pipe (copper) through which heat is transfered to the shell material. The shell material is a solid having a thermal conductivity of 1.5 W/(m*K). I am developing a 3D model to...
12 December 2014 8,449 11 View
In complex numerical models having mesh elements nearing a million, its highly impossible for GIT due to time and constraints. So is GIT necessary or is there any alternate option?
12 December 2014 5,477 21 View
Is there any attempt previously made for an in-house solar thermal power plant? Also what challenges/factors restricts the development of such smaller power units?
11 November 2014 549 4 View
With the output of XRD, we can get any information relevant to Phase Change Materials of Latent Heat Storage?
11 November 2014 2,075 3 View
I am working on the development of a novel material as a part of my research work which needs the preparation of many samples / mixtures. Analyzing all the samples for the detailed physical...
11 November 2014 2,353 6 View
I have found different combinations / proportions provided in the literature for the Hitec XL commercial ternary nitrate mixture salt. Ca:K:Na-NO3 (wt%) ==> 44:44:12 (Sandia National Labs),...
11 November 2014 8,637 5 View
Can anybody explain pressure point constraint with a practical example in terms of CFD?
11 November 2014 7,344 7 View
I have a coupled darcy flow and heat transfer in porous media module in COMSOL. I would like to independently know the temperature of the fluid and temperature of the porous medium separately,...
11 November 2014 1,449 8 View
My model consists of a fluid flow (hot) passing through a packed bed (cold) of certain porosity exchanging the heat. The fluid flow is having both temperature as well as flow conditions. How to...
11 November 2014 1,507 6 View
I am working on flow through porous media. Flow characteristics can be solved using Brinkman Equations physics and Heat Transfer characteristics can be solved using Heat Transfer in Porous Media...
11 November 2014 5,446 3 View
I have a workstation with dual xeon processor with 64 GB RAM. I have installed COMSOL Multiphysics as per the Installation Guide. But when I checked the CPU usage, I found that only one of the...
11 November 2014 6,570 6 View
There are many research papers on study of flows and heat transfer through porous medium. Can anybody have (or links) some basic introductory material on this subject? There are many equations -...
11 November 2014 6,282 3 View
I am not able to see "Outflow" in and Fluid Flow and related modules like Laminar Flow, Brinkman Equations. But I am able to find in Heat Transfer modules. May I know what exactly Outflow means...
11 November 2014 5,050 6 View
I know the properties like density,specific heat, latent heat, viscosity and thermal conductivity of NaNO3, KNO3 and Ca(NO3)2. I am using a ternary mixture with a new composition which doesn't...
11 November 2014 1,851 3 View
I have a workstation equipped with a Dual Intel E5-2650 v2 processor and 64 GB RAM. I am running heavy computational simulations which needs about a month for a single run. I heard that RAM Disk...
10 October 2014 1,376 15 View
K grade copper tubes are regarded as the highest thickness copper tubes in general. Is there any copper tube grade having thickness greater than K?
10 October 2014 5,867 2 View
I need to measure the hot air flow in my setup which is at about 600 °C having an approximate flow rate range of 120-180 m3/hr. At this high temperature, which type of flow meter is recommended?
10 October 2014 8,022 1 View
I am running a conjugate heat transfer problem in ANSYS Fluent with an i5 CPU & 8 GB RAM. The entire simulation takes about 3-4 days. The concern is that ANSYS Fluent is not fully utilizing...
10 October 2014 4,487 19 View
With XRD reference data, we can check the identity of the salts. Hence can anybody share the XRD data for certain phase change materials like NaNO3,KNO3,Ca(NO3)2 and their mixtures? Is there any...
10 October 2014 1,842 3 View
For heavy simulations, it is necessary to see the results/solutions sometimes in the middle and after reviewing it, the simulation can be started from where we stopped. Is this option available in...
10 October 2014 7,853 8 View
I have ran my transient COMSOL Simulation from 0-900 s with a time step of 1 s. After seeing the results, I understood that, it should be run for 300 s more. Is it possible to continue from where...
10 October 2014 1,425 1 View
I am designing a cylindrical air heater for heating the air from 30 °C to about 500 °C. The flow rate is about 150 m3/hr which is induced by a blower. The diameter is about 10 cm. I want to...
10 October 2014 3,578 28 View
Can any body share me some references which contains temperature withstanding data of concrete mixtures?
09 September 2014 2,280 10 View
Vertical 2D axisymmetrical modeling is the default in COMSOL Multiphysics. Whether horizontal 2D axisymmetrical modeling is possible? Please explain the same?
09 September 2014 5,039 17 View
In cartesian coordinates, a particle position is denoted by (x,y,z) and velocity field is denoted by (u,v,w). Similarly a particle position is denoted by (r,phi,z) in cylindrical coordinates. But...
09 September 2014 6,160 1 View
I am trying to prepare a homogenized salt mixture from 2 salts of certain proportion. Lets say that the melting point of the salts are about 300 °C & 400 °C. It is a bit difficult for me to...
08 August 2014 3,752 8 View
I am modeling a simple conduction cum fluid flow problem in ANSYS Fluent. Hot Fluid (say water) is passing through the inner tube of a 1m length double pipe heat exchanger having the solid (say...
08 August 2014 2,332 8 View
Exergy / Available energy is being lost in several engineering processes. It is of prime interest in the field of heat transfer. Is there any numerical models (or) some minor numerical works...
08 August 2014 9,258 6 View
I have a set of both experimental and numerical values (say for every second). What are the different ways of finding the cumulative deviation between the values? Which can be considered the best...
07 July 2014 5,814 9 View
I need to prepare a homogenized binary salt mixture from 2 salts. For getting a homogenized salt mixture, I need to heat above the melting point of the salts (about 350 °C). Can anybody suggest...
07 July 2014 2,036 2 View
Is it possible to weld SS with cast steel without any weld defects? If possible, which welding process will be preferable?
07 July 2014 3,949 6 View
I need phase diagrams of Ca(NO3)2 - NaNO3 and Ca(NO3)2 - KNO3. Can anybody share the same or give the corresponding reference
07 July 2014 6,167 6 View
Latent heat data is hardly available in the literatures which I have gone through. Can anybody give me the value with a reference. It will be really useful in my research.
07 July 2014 7,553 4 View
I would like to analyze a shell-and-tube heat exchanger in ANSYS Workbench. How to draw the same in ANSYS without importing from AutoCAD / ProE. Is there any video / pdf tutorials available for...
07 July 2014 4,034 13 View
I am using an oval gear flow meter for measuring the hot oil stream having a temperature of 200 °C moving in a 2" pipe at a velocity of 0.1 m/s - 1 m/s. Is there any other way of measuring the...
07 July 2014 1,195 9 View
I have sodium and potassium hydroxide salts but I am not able to differentiate the both. Is there any simple tests by which we can identify the salt.
07 July 2014 9,645 8 View
Sodium Hydroxide is a highly corrosive salt. How to safeguard the neighbor materials associated with it from its corrosive action?
06 June 2014 9,186 8 View
Heat capacity of most of the materials is higher at higher temperatures. What is the reason behind this?
05 May 2014 5,556 4 View
Meshing is difficult for complex geometries with a low/medium end workstations. Which has the major share in meshing - CPU or RAM or a combination of both?
05 May 2014 3,761 19 View
Assume water flows outside the metal holder at certain flow rate. Is the above situation practically possible? Whether the lesser melting point material will not melt? Any body know some practical...
05 May 2014 8,046 7 View
As per a WHO report, by the end of 2012, 64% of the global population used improved sanitation facilities which means almost 1 of every 3 person still have less / no access to proper sanitation....
05 May 2014 1,658 3 View
I have a motor overload relay attached to a motor which is connected to a pump. The relay is set for 10 A. But when the current supply to the relay is 8 A, it trips. I have checked the current...
05 May 2014 3,669 8 View
See above
05 May 2014 4,271 1 View
Maintaining the oil level in the thermal circuit is important. If oil gets evaporated at a slower rate, after a period of time, there will be a lack of oil and need to be filled. But does this...
05 May 2014 1,749 2 View
What is the relation between the mesh elements and degrees of freedom? Whether both of them are dependent of the shape?
05 May 2014 3,067 2 View
I am not able to give convergence criteria in COMSOL Multiphysics.
04 April 2014 6,800 7 View
Thermocouple probes are easily damaged and leads to incorrect temperature readings. Is there any way to safeguard it?
04 April 2014 2,763 4 View
I am planning to do DSC experiments to make a phase diagram of a binary salt mixture. I know that with the melting point data from the DSC, we can draw the liquidus line. But how to draw lines...
04 April 2014 1,859 3 View
Consider a 2 meter SS316 tube of some diameter (say half inch). This tube is kept inside a partitioned rectangular container as shown in the attachment. There are about 3 partition plates which...
04 April 2014 2,957 10 View
nitf.HRef =...
04 April 2014 2,424 0 View
COMSOL Multiphysics is an emerging CFD software and many researchers have started using it for making numerical simulations. Still learning a new software is a bit time consuming and challenging...
04 April 2014 1,999 18 View
There are many chemical databases containing the property details of many compounds. But the good databases are not free. So which is the best and freely accessible chemical database? Also let...
04 April 2014 1,265 2 View
The main hot fluid MS pipe line is 40 mm. I want to cool the fluid by passing the fluid through 3 copper tubes of 12 mm dia (brazed to the main fluid line) and water over the copper tubes and then...
04 April 2014 5,395 12 View
Consider a shell-and-tube heat exchanger with some no of tubes and 1 meter length. I want to find the temperature variation of the fluid in the tubes experimentally by finding its temperature at...
04 April 2014 7,881 14 View
Some numerical problems need a fine mesh for solving it rather than a coarse mesh which is acceptable. But some numerical problems are converging for a normal (between fine and coarse) and not...
03 March 2014 897 19 View
Sample manuscript will be useful and makes the writing process easy. Why have many journals not thought about this? Any specific reason ?
03 March 2014 6,265 2 View
I am writing a manuscript for one of the quality Springer journals. The Author Info Pack is very exhaustive but not contained the basic things like - whether manuscript be written in a single file...
03 March 2014 2,306 1 View
To avoid cheating while procuring raw materials, is there any test to check the original material - SS304 and SS316?
03 March 2014 7,578 11 View
Please provide some examples if these numbers apply to complex profiles.
03 March 2014 9,645 5 View
Welding introduces contact resistances in the joint between pipe and external horizontal fin. Any other better methods to join the fin with the pipe? Say Copper fin with copper pipe (or) mild...
03 March 2014 701 6 View
Many pressures will be exerted on the tank during phase change of a material. To my knowledge, 1) the air given for volume expansion will exert some pressure, 2) sensible thermal expansion 3)...
03 March 2014 3,545 1 View
I have a heat exchanger of cubical shape (say 1m * 1m * 1m) containing a material heated by means of a heat transfer fluid passing through the pipes in it. The surface temperature of the cubical...
03 March 2014 385 33 View
I need vapor pressure data or calculation of vapor pressure for molten salts.
03 March 2014 9,173 1 View
I want to know in which applications we have to use film temperature and bulk temperature?
03 March 2014 5,372 8 View
Out of the solvers available like MUMPS, PARADISO, SPOOLES, etc. which is best suited for solving highly non-linear problems
03 March 2014 5,553 3 View
To find the Grashof Number, the characteristic length is needed. How do I find the characteristic length of the annular region of a concentric cylinder of outer dia D and inner dia d? (Assume that...
03 March 2014 887 6 View
Almost all engineering scenarios can be converted into mathematical problems. Advancements in the engineering research/applications are hindered due to unsolved/only partially solved mathematical...
03 March 2014 3,954 94 View
We can use LMTD and NTU method for finding the performance parameters in heat exchangers when both the fluids are moving. What to do if one fluid is stationary/stagnant (say shell side)?
03 March 2014 586 6 View
Say hot water (1m*1m*1m) of approximately 80 °C is kept 2 meter above the cold water (1m*1m*1m). Hot water is passed through a single tube heat exchanger through cold water which is stagnant by...
03 March 2014 5,924 1 View
What is the conceptual difference between crystallization and solidification? Crystallization is the formation of crystals, but when cooling a liquid metal are the terms synonymous?
02 February 2014 1,559 10 View
Normally most of the phase change materials undergo subcooling while solidification. Is there any way to model the same numerically?
02 February 2014 7,470 5 View
Does the thermal boundary conditions have an effect on the thermal conductivity of the material? I have attached a basic problem to understand the calculation of effective thermal conductivity of...
02 February 2014 6,001 2 View
I am finding difficulty in simulating melting or solidification of phase change materials.
01 January 2014 795 10 View
If both high temperature and pressure boundary conditions should be given for solving a problem using COMSOL / ANSYS, is it feasible?
01 January 2014 408 12 View
By consider a heat pipe of inner radius r1 and outer radius r2, what will be its effective heat transfer surface area considering its thickness?
01 January 2014 6,420 7 View
I know the velocity, inlet and outlet temperature of oil flowing through a pipe. Now how to find the heat transfer coefficient of the oil flowing through the pipe? What are the steps?
01 January 2014 7,529 10 View
I need to store some inorganic salts such as NaNO3,KNO3,NaOH and KOH. Which type of container & container material will be best suited for this?
01 January 2014 9,314 3 View
Generally it is recommended to keep the expansion tank (deaerator tank) at a certain height (say 6-9 feet) above the pipe line. What is the concept behind this?
01 January 2014 9,684 16 View
Thermal expansion of oil has been considered by incorporating an expansion tank (deaerator) in the pipeline. Whether vapor will form while heating? Even if vapor formed, whether expansion tank...
01 January 2014 1,126 4 View
I need to cool oil passing through copper tubes with water. For more surface area, I am planning to make copper tubes spiral. Whether spiral copper tubes will be available readily or do we need to...
01 January 2014 2,566 5 View
To reduce the computational cost, we normally solve any systems for quarter / half of the domain. Is it possible to reproduce / generate animation containing full body from the solved results?
01 January 2014 4,565 5 View
I want to check the nature of flow in the shell side of the shell-and-tube heat exchanger. Hence I need to know the characteristic length of the shell-and-tube heat exchanger to calculate the...
01 January 2014 8,048 1 View
What is the concept behind Vapor pressure? If its high/low what is the impact? Water / Oil - which has high Vapor pressure and why?
01 January 2014 3,437 3 View
I need to know which method will give an easier and good result for finding melting point and latent heat of fusion.
01 January 2014 8,203 3 View
I want to do a DSC-TG analysis for a salt mixture. My question is how to prepare the sample for finding the melting point,latent and specific heat? Is mere weighing the individual salt and proper...
01 January 2014 8,074 2 View
I am having 4 inorganic salts - NaOH KOH NaNO3 KNO3. I want to prepare a salt mixture using any of these 4 salts which should have melting point in the range 175-215 °C.
01 January 2014 3,318 6 View
How can we measure/quantify the corrosiveness of a material (inorganic salt)? Is there any easy compare with a reference material like water?
01 January 2014 3,488 5 View
Density of a material of course changes with temperature. I am planning to run a numerical simulation which involves melting of phase change material. I need density data at certain points to...
01 January 2014 4,843 8 View
I am planning to run a numerical simulation which involves melting of phase change material. I need thermal conductivity data at certain points to input the numerical model to get more exact results.
01 January 2014 4,310 5 View
Sodium Hydroxide is becoming wet when contacted with atmospheric air. What is the reason behind this? Any methods to reduce this? Also which type of container is more suitable for storing it...
01 January 2014 9,669 8 View
For any inorganic salts, there will always be a difference in the melting and solidification temperature which I have noted from some DSC results. What is the key concept behind this? In salt...
01 January 2014 1,094 5 View
I have done a DSC-TGA analysis of an inorganic salt. Instead of taking a lesser amount (5 - 10 mg), i have wrongly placed a sample of 20 mg and done a heating up to 500 °C. Due to this the...
01 January 2014 4,640 7 View
How to first prepare 50-50 KOH-NaOH salt mixture as both are highly hygroscopic? Is hermetic sealing a good option? How hermetic sealing can be done for preparing a mixture? Also because of high...
01 January 2014 1,825 5 View
I have the output files from the DSC-TGA analysis of an inorganic salt. Could any one can comment or share files related to the calculation of melting point, latent heat, and specific heat from...
01 January 2014 7,709 15 View
I am doing some experiments on melting some inorganic salts. During heating as well as melting, certain expansion will occur due to the increase in the temperature. So I need to find the...
01 January 2014 5,250 31 View
During melting of an inorganic salt in a container, conduction is the dominant mode of HT initially. After some time, the convection will be the dominant mode of HT. How can we quantify both the...
01 January 2014 1,969 3 View
Whether "Grid Independent Test" and "Mesh Convergence Study" are synonymous or any difference exists between them? Can anybody explain?
01 January 2014 2,767 9 View
Normally, apparent and effective heat capacity methods are used for melting or solidification simulation of phase change materials. What are the differences between them? Which is preferable, and why?
01 January 2014 5,033 4 View
In a thermal oil pipe line, I want to measure the flow rate of the oil. Can I place my oval gear flow meter just before the pump? I assume that after the pump, due to turbulence, flow rate...
01 January 2014 7,989 10 View
What is the major criteria in the selection of tube size in heat exchanger?
01 January 1970 6,061 17 View
