LS-DYNA Examples

LsDynaBirdStrike.avi

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 www.dynaexamples.com !!

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 http://www.rolls-royce.com/interactive_games/journey03 for a full, richer experience.

Thermal efficiency vs Propulsive efficiency : Who will win?

commercial_Engines
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!