[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Pterorhynchus dewlap

----- Original Message ----- From: "MICHAEL HABIB" <habib@jhmi.edu>
To: <dinosaur@usc.edu>
Sent: Thursday, February 02, 2006 3:42 PM
Subject: Re: Pterorhynchus dewlap

In fact, with their high-aspect ratio wings and excellent lift coefficients, many of them probably flew very quickly > (being large helps in that arena as well).

It does. The big azhdarchids had wingloading as high as equivalently sized sailplanes and flew at about the same speeds. If you want to get a handle on Qn, Arambourgiana, or Hatzegopteryx performance, take a look at the Carbon Dragon, the WindRose, or the SparrowHawk. Vne is different, but much of the other stuff is close enough for government work. These suckers were fast. They had to be to be to support their weight. Keep in mind though that pterosaurs have a distinct upper speed limit as the CL decreases and the aeroelastic number declines with speed. Go too fast and the wings flutter.

Granted, they might have had less drag and moved more efficiently without the crests, but (as I mentioned in my last post, and as Jim also alluded to) the L:D ratio was probably good enough to get by.

Yeah. I wouldn't expect it to be any better than need be. They had good wings, so could afford crappy excrescences like big heads, long necks, and other such stuff.

I would flip the point of view a bit and say that pterosaurs were so efficient that they could afford big nifty crests, > rather than saying the presence of large crests implies low performance.

I agree. The presence of large crests, big heads, and long necks implies very good performance otherwise. I think even an albatross would have trouble performing if you stuck an azharchid head and neck on him. In passing, some pterosaurs had higher aspect ratios than albatrosses do.