Simulation of Thermal Flows in ANSYS Fluent

In this tutorial, I will explore the case of a pipe (or a channel) further adding in the temperature boundary conditions. The concept of hydrodynamic and thermal boundary layers would be described in this tutorial using an example from the book of Cengel – Heat and Mass Transfer. I will also teach you how you can plot any variable such as velocity or temperature across any cross-section. This tutorial shall serve as a beginner level introductory lesson for a student.

Part 1:

Part 2:

(Read this post on MultiEMOtions Android App)

Life and Turbulence

This article is meant to be included in my college’s magazine so the examples given here are more relevant to a college student, however, you’ll still get an idea of what I am trying to say once you make your way through these three paragraphs.

Being a Mechanical Engineer in the making, I feel it irresistible to correlate what I see to what I experience. From what I have learnt so far in life, if one do anything with passion, then the similar principles can be used to lead a better life. Sports develop your character, arts develop your creativity. Even a chain-smoker, at some point, develops the awareness that lung cancer and blindness are not too far behind. But usually, he/she neglects it. My experiences with fluid dynamics have provided me an insight to a better day-to-day life and you do not need to be an engineer to understand what I have to say.

There are two kinds of flow that we usually work with: laminar and turbulent. Laminar is a very structured sort of flow in which layers of fluids flow over one another. Think of your classmate who when given a certain condition, will always respond the same. Class bunk karte hain? NAHI! (Let’s bunk the class today? NO!) Bhai aaj class mat ja please? NAHI! (Don’t go to the class bro? NO!) That is what laminar flow is. If you do an experiment over and over again, you will get exactly the same results. Quite a good-boy kind of flow. On the other hand, turbulent flow is characterised by its chaotic nature. No matter how accurately you try to experiment, you can never get two exactly same turbulent flows. Fluctuations are what makes it unique. Though there exists a constant mean value of almost every parameter (like the laminar case), but once the fluctuations come into the picture, the whole story changes. It’s like your attendance at the end of the semester. On an average, it would be somewhere around 70-75%, but if you plot it on a graph for all of your classmates, you know how terribly fluctuating that thing would look like.

I happen to have a theory which I would like to put before you. Our daily lives are just like this turbulent flow: chaotic, non-repeatable and unpredictable. At least for the human beings, I don’t think you can have any two days exactly the same in your entire lifetime. Can you? Fluctuations make up the problems we face, big and small. For someone not taking in the bigger picture, these fluctuations may never seem to fade and could occur endlessly. Have you not seen people complaining about their lives all the time? How about that friend of yours who cries “yaar kuch nahi padha (Hey I didn’t study a thing)” before every exam? Maybe, he’s just creating a pseudo-fluctuation to fool you! Or maybe not. However, as one zooms out, you might start to notice that constant happiness-line hiding behind these problems. You won’t realise it until you are brave enough to look outside the fluctuation box. Happiness does always exist, you don’t even have to ask for it. Once you make your way through the problems, one at a time, you’ll feel it growing inside. It’s like a friend who saves a desk for you despite you getting late in every other class. It’s like that friend who carries you through all of your break-ups. My message here is simple: problems are inevitable, suffering is optional. Think about it!

I’d like to hear your thoughts on my theory. Feel free to complement, amend and criticise it 🙂

Simulation of steady and transient flows over solid circular cylinder using ANSYS Fluent

For beginners trying to understand the basic implementation methodologies of Computational Fluid Dynamics (CFD), flow-over-a-cylinder is one of the classical problems to work with. This is because of the following:

  1. It has been widely studied in the literature, i.e. theoretically, numerically and experimentally for a variety of Reynolds number.
  2. It provides an understanding of the existence of boundary layers which was immortalised by Prandtl at the beginning of the 20th century.
  3. It has such a beautiful flow field (for the transient case) which is now formally called as the Von-Karman vortex street.

That being said, I am providing this tutorial for the people who are new to CFD and are interested in solving problems involving a Fluid-Solid Interaction (FSI). Take your time to watch it and don’t hesitate to ask me any questions.

Celebrating the launch of Windows 10 with MultiEMOtions Windows 10 APP

It is 29th July in here but the moment is yet to come in Redmond when Microsoft will make it’s brand new OS Windows 10 public, finally. I have been using the technical preview version on my Acer Aspire 5745 for quite some time and it has been a really good experience so far. Not only the desktop, I had my hands on the earliest technical previews of Windows Phone Mobile 10. I have been quite happy with the Windows ecosystem so far and I expect the same trend in future.

Coming back to the point. As some of you might have noticed that MultiEMOtions has apps dedicated to Android and Windows Phone. I am not an app developer but Microsoft has made it really easy for people like me to develop some basic apps using App Studio. I had developed the current app for Windows Phone 8.1 and Windows 8.1. But with Windows 10, one can use the same app on desktop as well as on the Mobile. So, for developers (I am gonna consider myself this time), they have to write their code once and it will work on devices of all shapes and sizes.

Microsoft has already added the option to develop apps for Windows 10 on App Studio and I was just porting the content of my Windows 8 app to Windows 10 app. Because in this way, my app can be accessed to many more people once Windows 10 will arrive and I expect to reach out to more people, in a technically better way. I am quite excited for Windows 10 and Windows 10 Mobile because it really seems much cooler than the previous editions of Windows. Once it arrives, I hope my readers are gonna give this new app a try considering all the work I have been doing, not only for the content of MultiEMOtions but also for the ways in which it can reach you.

MultiEMOtions Windows 10 APP: http://1drv.ms/1fFSp5C (OneDrive link)

Chowmein, Chaomian

We all love fast food at some point of time. And when it comes to fast food, it is hard to resist the Chinese fast food. It is such a delight to tummy after all. I think that it can be found almost in any country (of course if that is not an anti-China country). Chinese fried noodles are famous as Chowmein in many parts of world. Being in India, these can be found in many parts with taste varying from dull to spicy. Till the time I came to Taiwan, I knew them as Chowmein thinking that there is no certain meaning behind this word.

Once in my last semester, when I was studying Chinese and was discussing something with my friend, then I came to know that the modified word Chowmein is actually derived from Chaomian. In Chinese, Chao means fried and Mian stands for noodles. So, it actually is Chaomian in Chinese and while it is exported to somewhere else, it becomes Chowmein. I wonder why? Not only the name, I have found that the style of cooking these fried noodles is different. Indian Chowmein usually is very spicy while on the other hand, Taiwanese Chaomian is a bit sober in taste. It could be different in other countries where noodles are included in restaurant’s menus.

Are you a Chinese fast food lover? Do you like Chowmein or Chaomian? Let us know in the comments 🙂

Heading on to the final exams

This semester is perhaps my last semester in which I have to take classes (if I do not fail) because I would be completing my credit requirement for graduation. Ahead lies the year of core research which I am waiting for. But still, there is a bridge for me to cross. Final exams. I am not so worried this time as much as I was in last semester. This could be dedicated entirely to the courses that I have chosen. Out of four classes, I only have one written exam and all other courses include some kind of project or presentation. I remember how I spent a sleepless week last semester.

This semester has been quite special. I have been taking courses from National Chiao Tung Universtiy (a sister university of NTHU). It is quite cool how one can take courses from other universities. Because some courses which are offered in English are better there. I have one subject called Heat Convection which is quite theoretical and I am slightly afraid of that because I count myself as one of the poorest mathematical guys. But I am just waiting for the last night and you can understand why 😀

Apart from it, I enjoyed playing badminton this semester. Last semester, I tried to learn swimming which ended up in a fail because of me not getting to understand anything what my teacher used to teach. I am planning to give it one more try next semester.

Right now, it is less than a week before all the project submissions and exams bombard themselves onto me. Well, I am pretty ready too (over-confidence, eh).