Floating disc brakes for hi-speed airplanes

[willpittenger]

Many years ago, I thought of what I called "double disc" brakes. I turned the calipers into the second rotor. I knew air cooling would be nearly impossible -- so I specified water cooling using the rotation of the wheel as a pump.<br /><br />Recently, I was watching a show that showed some new types of brakes being tested for cars. This type of brake used one caliper to push the rotor (which floats, hence the name) into a caliper on the other side of the rotor. Like my double disc concept, each caliper brakes along the entire surface of the rotor. Unlike my concept, supposedly, this type doesn't need cooling at all.<br /><br />So I find myself wondering about how these floating disc brakes would work on hi-speed aircraft. The show only showed the brakes on a car. As many readers of M&L may recall, I had discussed a large spaceplane that would have a 200+ kt stall speed -- with its STOL systems active. Without STOL, 300+ kt would be more accurate. With STOL, the plane had to handle the same runways that commercial airliners use. Without STOL, it would have to settle for runways like those at Edwards, White Sands, and possibly the shuttle runway in Florida.<br /><br />As is, I was worried that trying to stop that plane in such a short distance from such high speeds might cause the craft to spin. So I added a lot of bogeys (10+ rows) to the main gear. That increased the braking surface for the rear half of the plane serving as an anchor to prevent those spins.<br /><br />Now do people believe such brakes as that show discussed would help such hi-speed landings? <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[jschaef5]

300 knot stall speed?<br /> <div class="Discussion_UserSignature"> </div>

 

[billslugg]

Will<br />It is all in the heat transfer. You have got to get rid of the heat. With a small caliper, the majority of the rotor surface is exposed to the air, thus can exchange heat via radiation (very minor at these temps) plus forced convection. If you cover up the entire rotor you have no where for the heat to go except through the calipers, unless you have cooling channels inside the rotor. <br /><br /> Downside of small caliper is that it will reach a higher temperature given it absorbs the same number of BTU's as a large rotor. <br /><br />Actually, given the short amount of time that an aircraft will be using the brakes, heat transfer to the atmosphere is not going to amount to much. Water cooling internal to both rotor and stator with full contact areas on both is the way to go.<br /> <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>300 knot stall speed?<p><hr /></p></p></blockquote><br />If the STOL is system was unavailable. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>