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cookedinlh

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Everything posted by cookedinlh

  1. Thanks Kent . still looking at the options. We plan to place a big "turbulence generator" right under the rear seat . . a turret ball about 190cm diam . . . so anticipating the NACA will just not like the view. cookedinlh Dave Cooke
  2. Hi Wayne . .  found your "downdraft" mods interesting and would like to talk if you have time. I'm modifying one to be MRPV (Manned RPV) and need some advice

    Thanks
    David Cooke

    Chief PILOT, UAVs

    ITPSCanada.com

    david.cooke@itpscanada.com

    IMG_1757.JPG

  3. Anyone know if this MOD / kit is available still . . is it only from Australia Thanks cookedinlh
  4. No Apology necessary . . honest mistake . . .never heard of Terry . . but will look him up now too. Thanks for the reference Cookedinlh
  5. Woah . . . sorry Bruce . . that was a direct (Copy Paste) from a post by "Richard Schubert" . . . must be another Long EZ builder . . here's the whole quote (Italics). ======================Cookedinlh=============================================================== Richard Schubert said: Well, dynamic pressure is equal to 1/2 * the density of the fluid * the velocity squared. Lets say 150 mph(thats indicated) 150*5280/3600= 220fps Density of air = 0.002377 lbs/cuft (approx.:) ) so (0.002337)(220)(220)= 113lbs/sqft of pressure divide by 144 for sqin =0.786 lbs/sqin atmospheric pressure = 29.92 in mercury or 14.7lbs/sqin 2.03 in mercury/1psi 0.786*2.03= 1.6" max theoretical pressure gain YMMV "Just finished a fluids course and I couldn't resist":D Thats a lot of numbers. On my IO360, 1.2 is about what I see on the manifold gauge when I switch from the filter to the direct ram air. Numbers aside the difference between the two on a sea level take off is worth every bit of the little drag of the scoop. the difference starts at about 150 mph and makes about a 500 ft./ min increase in climb rate. As to the drag issue, the air has to get to the engine somehow. even if it comes in with the cooling air into the cowling it is still creating drag. if some of the air goes for engine intake then that is air not used for cooling. the total of intake and cooling drag is the same weather it is in one scoop or two. why would you not take advantage of the higher pressure air and pipe it directly to the intake. COWL AND WINGLET MODS: Finally got to check my cowl mods. The two exit scoops look very promising. You will notice that I have a fairly tight opening around the prop hub; I did this because I do not believe there is good exit flow around the hub of a pusher based on oil flow I have seen inside the cowl and other indications. Originally (2nd pic) , I believed I would get good exit flow from large openings around the exhaust pipes at the edges of the cowl but that did not seem to pan out. The new exits allow air to blast out of the cylinders and return to freestream by the most direct route with the minimum turns and turbulence, I think. (pics 3,4). In addition I think I've added a few sq. inches of exit area. Before, I was only getting about 4 to 4.5" of water differential across the cylinders. I am now seeing about 6" and 330 deg. at moderate cruise speeds. I will have to wait for a hot day for a full test. Manometer setup, pic 5. I added an adjustable door on the oil cooler. At current temps--about 55F--I have the door cracked a bit to get 180 degree oil temp. This oil cooler duct system is not the easiest to install but it seems to work well. (pic 6)
  6. All great comments guys thanks for pitching in so readily. Yes the NACA was expected to be a problem with this FLIR mount and we'll likely have to find a (different) better solution for cooling and breather air. Going to have to do some flow analysis likely and design a new intake. Does anyone know the target intake airflow that's needed for a cool running engine at max cruise? Richard Schubert did a nice simple calcs and came up with at max pressure of 0.786 lbs/Sq Inch at 150mph . . . but how many cuft/sec of air is needed for carb and cooling if you want the cylinder heads to remain as Lycoming says 65% below of rated and <400F oil 165F-220F Cookedinlh
  7. Hi Bruce... did you say you still have an original style lower cowling with that scoop shape?....where is it located? cookedinlh
  8. Just for training FlightTest Engineers... needs the most stable mounting point on longitudinal centreline. Seems like the original scoup shape with some laminar flow fairing behind the turret might do it... or perhaps top mounted intakes but that maybe just complicating things more....it’s to become a single pilot a/c with instrumentation in back to allow for 2-3 hr Telemetry mission
  9. Thanks for that link and photos Kent . . that helps a lot . . the underlying concern in because I plan on putting a belly mounted (~1ft diam sphere IRST infrared Search and Track turret) right behind the AirBrake and that's going to obstruct the flow even more so I'm trying to anticipate if I can do anything to prevent further overheat issues. Cookedinlh
  10. Here are a couple of other views . . . NACA yes I could not remember the name . . it makes for a nice slick flight and look but it dosen't "pass wind" very well
  11. The issue is engine temperature limits . . I'm limited to about 75% sustained throttle except for t/o roll before it starts to overtemp in cruise . . it's just not getting enough air. Not sure why the builder ( not me) decided to go with that version since it's very solid somewhat overweight airframe and needs all the power it can muster for any more than mild performance w 2 pax and fuel Will try getting a better photo when I'm back next week . . thanks for all the quick response guys Cookedinlh
  12. Anyone know if parts like this are ever up for sale . . should a cowling from a/c A be able to fit a/c B or is that unrealistic . . . do I have to make a new one from scratch? The one I have has been modified beyond repairing it to original flow cross section. It currently looks like this Anyone? Thanks Cookedinlh
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