LS-DYNA Examples


Well this one will be a short post.

If you are into analysis and by any chance use LS-Dyna analysis software tool, then I have a site to recommend to you all.

It’s !!

Yes as the name suggest there are numerous downloadable ls-dyna examples on this website.

Even if you are not into Ls-dyna, but are in analysis, I suggest you take a tour of this website. You will come out by learning something useful.

That’s it, if you know about other sites that might be helpful to other users of this blog, please do name it in comments.


Using Algorithms to Evaluate Designs for Jet Engines and Aircraft

Algorithms and Gas turbines
Just a quick update regarding two of my favorite subjects, algorithms and Gas turbines, so check this out.

In this free webinar, Dr. Charles Roche of Pratt & Whitney will outline how algorithms can be used to weigh design decisions. The results have led to design ideas that changed the industry.

Dr Roche will draw on case studies such as how Boeing scrapped thrust reversers in their KC-46 and how Embraer selected their engine for the E-Jet E2.

Register Now

Journey Through a Gas Turbine

Sitting in the training room, looking at the projected GA’s of Trent XWB, surrounded by a white board littered with T-S diagrams and gas turbine cycle equations and hearing Mr CJB, Rolls Royce performance specialist for 30 years, gas turbine training couldn’t be better.

Had a really gruelling and most awesome week long training session. The lectures were instructive and the lecturer inspiring. Loved every bit of it.

Somewhere in the middle, got reminded of a video, that I saw when I began working for Rolls-Royce. Journey through a gas turbine. Its showed a beautiful animation of journey of air particles through a gas turbine engine.

Came back home and searched it on the Internet. Strangely it’s was no where to be found. Not on YouTube, not on Vimeo. Not on Rolls-Royce website.

I loved that video. 😦

Then found the next best thing at Rolls-Royce website, but there was no way to share that. So here’s a screen-grab of the video.

This screen grab is low-res video of Rolls-Royce Journey through the gas turbine, visit for a full, richer experience.

Thermal efficiency vs Propulsive efficiency : Who will win?

If you love aviation, then flightglobal is one publication that you can’t miss. Ever since I have been in this industry, I am a regular visitor and reader of flightglobal. I specially gobble up anything related to gas turbine engine.

And have come to love and eagerly wait for the yearly commercial engine report that flightglobal comes up. This years update is great, specially the war between Leap 1A vs PW1100G

Here’s an brief extract.

The blisks, the new materials and the two- stage high-pressure turbine allow CFM to vastly improve the thermal efficiency of the Leap, yielding a double-digit improvement in fuel efficiency with a conventional architecture for a narrowbody aircraft engine.

If the Leap architecture is intended to optimise the thermal efficiency of the engine, P&W’s PW1100G is mostly aimed at improving propulsive efficiency. There are generally two airflows in a turbofan engine – one that travels through the core of the engine and one which bypasses the core. The former is used mainly to drive the engine, although a small amount generates thrust. The latter, or bypass airflow, generates the majority of thrust.

A simple way to make the engine more efficient in generating thrust is to increase the amount of airflow that bypasses the engine core, or the bypass ratio. The only way to increase the bypass flow is to enlarge the diameter of the inlet fan, which is connected by a shaft to its power sources in the low-pressure turbine.

In a conventional engine architecture such as the Leap, the low-pressure turbine and inlet fan rotate at the same speed. As the inlet fan diameter widens, the tips of the blades spin faster than the speed of sound, reducing efficiency, and causing noise and vibration problems.

Instead, P&W introduces a reduction gear on the shaft that decouples the rotation speed of the high-pressure turbine and the inlet fan, allowing the latter to spin at one-third the speed of the former. As a result, the PW1100G has a bypass ratio of 12:1, twice the 6:1 ratio of the V2500. The reduction gear also reduces the load on the low- pressure turbine. The job of spinning the inlet fan and booster stages on the CFM Leap requires seven stages in the low-pressure turbine. The PW1100G inlet fan is 10cm (4in) wider than the Leap-1A, but uses only three stages in the low-pressure turbine.

Top 5 posts

These posts have been the most popular for the first half of 2013!

Ever green post. Always stays at the top. Lot of people converting fortran into DLL’s!

3 steps is all that is needed to get a gif animation from matlab!

An GIF animation to explain the Gas turbine blade nomenclature! Will never forget this again!

Gfortran and Excel. This explains how to create fortran DLL in gfortran and call it with excel using a simple example.

Random numbers are everywhere. And this module in fortran to generate non-uniform random numbers is quite popular!

The Atoms of the Aerospace Industry

Google plus announced it. Facebook allows it. And sumsung galaxy S4’s camera has it as a standard feature.. Animated gif’s are back on the web.

And I couldn’t agree more as the post on How to create a quick gif in Matlab? is getting quite a lot of hits these days. So here’s one more animated gif for anyone and everyone who is interested to re-learn the nomenclature of a gas turbine blade.

Gas Turbine Nomenclature

Gas Turbine Blade Nomenclature

It’s a gif version of the powerpoint that I created sometime back.

And if you are wondering about the title of the post, you should read this….

Keeping a journal and being a journalist

At John’s blog The Endevour, read this great analogy. It struck a chord. I am an engineering person at heart and did software as an hobby, but now working on creating engineering software that other engineers use, I know for real what he is talking about.

One of the differences between amateur and professional software development is whether you’re writing software for yourself or for someone else. It’s like the difference between keeping a journal and being a journalist.

People who have only written software for their own use have no idea how much work goes into writing software for others. You have to imagine a thousand things a user might do that you would never do. You have to decide which of these things you will accommodate, and which you will disallow. And when you decide to disallow an action, you have to decide how to do so while causing minimal irritation to the user.

If you develop software and are into engineering, I strongly recommend John’s blog.

Top 10 Algorithms of 20th century!

As i was reading this old PDF mentioning the top 10 algorithms of 20th century, was pleasantly surprised to see creation of fortran compiler listed as one of them!

The creation of Fortran may rank as the single most important event in the history of computer programming: Finally, scientists (and others) could tell the computer what they wanted it to do, without having to descend into the netherworld of machine code. Although modest by modern compiler standards—Fortran I consisted of a mere 23,500 assembly-language instructions—the early compiler was nonetheless capable of surprisingly sophisticated computations. As Backus himself recalls in a recent history of Fortran I, II, and III, published in 1998 in the IEEE Annals of the History of Computing, the compiler “produced code of such efficiency that its output would startle the programmers who studied it.”

Interestingly being in aeronautical/aerospace industry, I have encountered most of the algorithms listed there. Do read the PDF report and see how many of them you have encountered?

Thermal Barrier Coatings in Gas Turbine Engines

My colleague was saying this the other day. In todays time, if one wants to learn about some subject, there is no shortage of material on the web.

So very true.

So if you want to learn more about gas turbine thermal barrier coating, then the videos by the national academies at are awesome.

Thermal Barrier Coatings in Gas Turbine Engines: The role of Fracture of Metal/Ceramic Interfaces Part 3
by The National Academies

This videos are lectures delivered by Prof. John W. Hutchinson of Harvard University.

Three PowerPoints to keep your kids engaged

Well you don’t need a programming language to create things for your kids.

There are these three PowerPoints that I prepared along with my 2+ year old daughter. She loved making and using it. And along the way she learnt counting and about colours!!

Click on the pictures to download the slides.




These PowerPoint’s were prepared on a lazy Sunday in Derby while munching home made pizza!! Still remember the fun we had!!

Aero engines of the 21st century: evolution or revolution?

Volvo Aero magazine asked this question to Vincent Garnier Vice-President Research and Technology at Snecma on engine development.

Your presentation at ISABE 2011 in Gothenburg was entitled “Aero engines of the 21st century: evolution or revolution?”. Which will it be?
Continue reading

Winglets – Hype or Science

winglets hype or science

Airinsight’s post Winglets a triumph of marketing over reality inspired me to dig deeper .

And i found this good pdf titled understanding winglet technology [PDF]. Very good and easy to understand for a non technical person.

Have a read, 7 pages of simple explaination of the winglet technology. Worth a read if you are interested in airplane technology.

Winglets – Hype or Science

winglets hype or science

Airinsight’s post Winglets a triumph of marketing over reality inspired me to dig deeper .

And i found this good pdf titled understanding winglet technology [PDF]. Very good and easy to understand for a non technical person.

Have a read, 7 pages of simple explaination of the winglet technology. Worth a read if you are interested in airplane technology.

Reasons behind Delays in Indian aerospace programs

Following are 5 indian aeronautical and aerospace projects that are delayed in time and exceeded estimated cost.

1. Light Combat Aircraft (LCA), Phase-II
2. Naval Light Combat Aircraft (LCA, Navy), Phase-I
3. Aero-engine Kaveri
4. Airborne Early Warning & Control (AEW&C) System
5. Long Range Surface- to-Air Missile (LR- SAM)

The following are some of the reasons for delay in completion of the above projects:-
(i) Ab-initio development of the state-of-the-art technologies.
(ii) Technical/technological complexities.
(iii) Non-availability of infrastructure/test facility in the country.
(iv) Non-availability of critical components/equipment/materials and denial of technologies by the technologically advanced countries.
(v) Enhanced user’s requirements or change in specifications during development.
(vi) Increase in the scope of work.
(vii) Non-availability of trained/skilled manpower.
(viii) Extended/long-drawn user trials.
(ix) Failure of some of the components during testing.
(x) Technology Denial Regimes.

This information was given by Minister of Defence Shri AK Antony in a written reply to Dr. K.P. Ramalingam and Shri Upendra Kushwaha in Rajya Sabha today.


The reasons 3,5,6 and 8 are almost as if Mr. A K Anthony is talking about my teams projects. 😉

The RB3025 – Rolls-Royce concept engine

While the world was buzzing about the launch of the new Ipad, flightglobal ran this story about RB3025. I was travelling during that time. Today got a chance to read more about this Roll-Royce’s concept engine.

Here’s are few salient points about the RB3025

The RB3025 concept is Rolls-Royce’s response to Boeing’s RFP on the 777X.

The engines builds on Trent 1000 and Trent XWB technology, but uses a Trent 1000-derived core, lean-burn combustor, composite fan and advanced materials in high-pressure elements of the core.

The RB3025 concept is rated at 99,500lb (440kN).

It has a 337cm (132in) fan diameter for the baseline 407-seat 777-9X, giving the power plant a bypass ratio of 12:1, and – according to Rolls-Royce – a “better than 10%” improvement in fuel burn over the GE90-115B engine and 15% better than its Trent 800.

David Nuttall says Rolls will take the next “year or two” of design work with Boeing to optimize the engine around the conceptual aircraft, requiring roughly six years ahead of a service entry to fully develop a new engine.

Rolls-Royce’s RB3025 engine concept provides a low specific thrust and “excellent” propulsive efficiency, says Nuttall, plus a 62:1 overall pressure ratio which would be the highest OPR in a commercial turbofan engine.

More stories on RB3025 available at the following links.

Boeing 777X Propulsion

Flightglobal magazine’s story on RB3025

Rolls-Royce steps up 3 shaft engine technologies

All Rolls-Royce stories at flightblogger blog

Rolls-Royce XWB’s maiden test flight



The engine for Airbus’ new A350 XWB jetliner made its successful maiden flight on 18 February, 2012. Installed on the A380 flying testbed aircraft, the Rolls-Royce Trent XWB powerplant demonstrated its performance and fuel efficiency during an airborne evaluation of more than five hours.

Source: airbus

Read more about it here