10/23 Raptor Video

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rv6ejguy

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Fix all the audio levels from different cams. Outside mics on airplanes are usually all messed up so you often just take the levels way down.

You certainly get faster as you learn more but most of Peter's videos don't get done in an hour.
 

Rataplan

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its flying again :) 125 kts 3000 ft . One 8 finished and I finished my coffee so back to work.
 

Rataplan

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He’s been able to fly long enough and high enough for a cross country trip. Looks like I was wrong.
I think he got smart and plays it (thanx God) save. Just making the 40 hours with half power to safe the engine.
 

Voidhawk9

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Cooling problems. Ok, makes sense. But what is the cause? Plumbing? Radiator?
Design and implementation of the entire system.
It has already been heavily modified to achieve the current level of cooling, including a big reserviour in the nose to dump cold fluid into the system to cool enough to take-off!
 

wsimpso1

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Cooling problems. Ok, makes sense. But what is the cause? Plumbing? Radiator?
Much discussion further back. Hard for me to be sure, but the summary seems to be:
  • Cooling duct design appears almost non-existent;
  • HX cores are too thick for this speed regime;
  • HX cores may have too little volume;
  • System design included shoving some heat to the fuel for takeoff and climb, completely neglecting that the fuel heat sink is way too small to do much of that;
  • A big coolant tank was added as a heat sink to buy some time during takeoff and initial climb;
  • Charge air intercooler was added to the coolant loop as a HX (way too thick a core and too small overall);
  • and some outlet area increase.
The result seen on cool days is:
  • Temperatures of oil, coolant, and charge air rise quickly past thermostat temps and are still rising quickly when he goes down to about 40-45% power;
  • Temp rise goes from quick rising to almost level off at around oil and water/EG limit temps, where PM then either flies level or does a very gentle cruise climb;
  • If the temps are not already in the death zone, a hot day will move them even higher into the death zone, with all the risk to fluids, gaskets, seals, etc.
On top of all that, the turbo scheme has taken much criticism for improper sizing, poor intercooling, restricted induction and exhaust paths, which has raised charge air temps and EGT's, and lowers power output, and also bodes for short engine life.

The test program has consisted almost entirely of takeoff, gentle climb, level off and fly gentle turns, descend and land. No time to climb, no handling explorations, no CG range explorations, no stall checks, really, no testing except putting hours on the engine.

You do know he is on his second engine of the flight program?

Billski
 

BoKu

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But what is the cause?
Raptor's cooling problems, like the majority of its other problems, and like the vast majority of engineering failures, are more the result of failures of imagination than failures of calculation. Imagining how things might go wrong is more important than precisely calculating how they should go right.
 

5761RF

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Lately there are many posts including such phrases as the California group, the new company, the investors, the production group, the new owners, stakeholders, etc.

As far as I can tell, these references are to an entity which only exists because Muller has made repeated vague mentions of it. Given the California's enthusiasm for requiring any commercial concern to report its existence and pay some sort of taxes for the privilege of being in the state, and separately, the intense scrutiny the project has generated in the experimental aircraft sector, I find it curious this entity has not been identified.

Since Muller intends to build millions of dollars of product to sell to the public, one must wonder.
 
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