Posted by: pterofd | January 4, 2010

New Year, Old Problems

Well the holidays are over and its a brand new year, so its back to work for the research group as a whole. While our lastest trip to chilly Beijing wasn’t quite as sucessful as we might have wished for, we got a nice look at the excellent Jeholopterus and Darwinopterus, amongst others, and gave us all a good excuse to sit down and talk pterosaurs for a couple of weeks within too many interuptions. Many thanks to my advisor David Hone for putting up with us for a couple of weeks (Hope the new office is working out nicely).

So with the dawn of 2010 there are too many aspects of pterosaur flight that would like to cover but for the immediate future i will have to be content with working on getting our initial results on the fixed wing models into print and  unveiling our “next generation” models – complete with mobile joints. The fomer of these two tasks is just waiting on one or two body simulations to look into the higher than expected drag  coefficients we observed, but will be polished off before the end of the month and will represent the end point for the first experimental phase of the project. The latter models will take the simulations more than a little closer to representing an actual pterosaur by allowing us to alter the wing shape/sweep, tension and camber – for those interested in which animals we are planning for use it will be a combination of Coloborhynchus (based off the specimen SMNK PAL 1133) and an azhdarchoid pterosaur, most likely Sinopterus. This should give us the best of the high-aspect ratio and low-aspect ratio configurations that pterosaurs used. Of course such a model would be all for naught without a “membrane wing” that can: a) change shape as the the fore and hind limb joints are altered and b) still retain enough tension to function as a reasonable lift producing wing.

Simulating the pterosaur membrane is certainly no simple task however this is the current fixation of project workers Steffie Moeninger (SMNK) and Julian Sartori from the ITV Denkendorf who are working towards a prototype membrane. They themselves have far grander plans for membrane development than the simple wing model  necessary for the next phase of the project but i’ll see if a can’t obtain some photographs of their textile experiments and pursude at them to elaborate a bit of their indivudal goals within the scope of the project. Needless to say the development of pterosaur membranes for industrial/commercial use is in itself an interesting field.

So for the immediate future expect to have more forthcoming posts on membrane simulation, jointed pterosaurs and finally some hard experimental data for people to sink their teeth into. Of course there are any number of other aspects i want to cover, not least the role of the uropatagium and tail during flight along with an updated bit on pterosaur crests which will be a bit more substancial than my own previous attempt (Elgin et al. 2008). Of course there is also Colin Palmer’s latest work on the biomechanics of the pteroid and propatagium (Palmer and Dyke 2009) which i hope to say a few words about.

So a happy new year to all of our readers and stay tuned for further posts.

PS. For all those wondering where on earth the great Quetzalcoatlus is and how we could have passed it over so far – we are in the process of getting a CFD simulation sorted out in collaberation with the University of Karlsruhe which will center around this taxon.

References:

Elgin, R.A., Grau, C.A., Palmer, C., Hone, D.W.E., Benton, M.J. 2008. Aerodynamic charaters of the cranial crest in Pteranodon. Zitteliana B28, 167-174.

Palmer, C. and Dyke, G.J. 2009. Biomechanics of the unique pterosaur pteroid. Proc. Roy. Soc. B. doi:10.1098/rspb.2009.1899, 1-8.

For all those wanting to know where the great Quetzalcoatlus is in all of these experiments we are hoping to get a CFD analysis completed in a couple of months courtacy of the University of Karlsruhe (or KIT as i suppose it should now more correctly be called).


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