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vincefrazier(at)gmail.com
Guest

Posted: Thu Nov 15, 2012 6:49 am Post subject: speed tape

Ernest,



If I recall correctly, putting speed tape on RV ailerons was rejected

by Van.  Even if you could figure out how to keep it in the slot, it

would likely ruin the great aileron feel of these planes.



Vince

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ernest(at)flmitigation.co
Guest

Posted: Thu Nov 15, 2012 7:02 am Post subject: speed tape

Thanks for the advice, would rather learn on here than in the air.



Ernest



On 11/15/12 9:49 AM, "Vince Frazier" <vincefrazier(at)gmail.com> wrote:



 	  Quote: 	
		  



Ernest,



If I recall correctly, putting speed tape on RV ailerons was rejected

by Van.  Even if you could figure out how to keep it in the slot, it

would likely ruin the great aileron feel of these planes.



Vince

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smokyray(at)rocketmail.co
Guest

Posted: Thu Nov 15, 2012 10:24 am Post subject: speed tape

Ernest,

  I have tried both Speed tape and Vortelator tape on my RV4 with very little noticeable gain. I'm not a speed freak but really appreciate efficiency in any aircraft.  I am actually more interested in capability at both ends of the speed spectrum and high efficiency in max range cruise flight. That said...

I consulted a Aero Geek bro of mine and he suggested several things I attempt for drag reduction. (None of which involved James cowlings, wheel-pants or plenums) After installing his improvements on my HR2 I noticed a 10-15 Knot increase in cruise speed at WOT. 



Here they are:



1. Wing-Fuselage fairing, large tapered trailing edge-fuselage fairing. (Also helped my RV4). 



2. Filling in and smoothing all control surface "end holes" including Elevator at both ends (My HR2 has RV4 tail feathers, these are the voids at  the ends of the control surface that are hollow) I simply removed them, filled with foam, sanded flush, painted and rebalanced. 



3. Closing propeller/spinner gap. (I used bicycle inner-tube rubber on the inside of my polished Cessna 310 spinner, cut to fit around prop blade and RTV'd in place. 



4. Installed Van's Pressure recovery wheel pants over my larger 380X150X5 tires and paid close attention to how the pant fit around the tire. I still have 4" ground clearance at the rear of the pant in level flight attitude but actually noticed a 5 knot immediate gain over the previous James Pants and they work great on my 1800' turf strip. 



5. Re-rigged all my control surfaces to be aligned inflight with wing tip trailing edge/flap with a 2 degree reflex. (Hey, it works on the Maule and the RV10!) 



All this gave my LyCon IO540 C4B5 GAMI Injected EI electronic ignition equipped HR2 the capability to cruise at 180 KTAS at 11,500 (at) 9.5  GPH LOP. 19"/2700 (WOT) produces just under 225 KTAS at 11,500' at 15.5 GPH LOP, caked mud, grass and soybeans on tailwheel cables notwithstanding!



Hope that helps!



V/R

Smokey



PS: I also installed the above mentioned improvements on my 150HP RVX Hybrid. At S.L. WOT 28"/2800 RPM it produces 177KIAS and 175 KTAS at WOT (at)11,500' Not bad for 1/2 the HP of my HR2!

--- On Thu, 11/15/12, Ernest Hale <ernest(at)flmitigation.com> wrote:

[quote]

From: Ernest Hale <ernest(at)flmitigation.com>

Subject: Re: speed tape

To: rocket-list(at)matronics.com

Date: Thursday, November 15, 2012, 7:01 AM



--> Rocket-List message posted by: Ernest Hale <[url=/mc/compose?to=ernest(at)flmitigation.com]ernest(at)flmitigation.com[/url]>



Thanks for the advice, would rather learn on here than in the air.



Ernest



On 11/15/12 9:49 AM, "Vince Frazier" <[url=/mc/compose?to=vincefrazier(at)gmail.com]vincefrazier(at)gmail.com[/url]> wrote:



[quote]--> Rocket-List message posted by: Vince Frazier <[url=/mc/compose?to=vincefrazier(at)gmail.com]vincefrazier(at)gmail.com[/url]>



Ernest,



If I recall correctly, putting speed tape on RV ailerons was rejected

by Van.  Even if you could figure out how to keep it in the slot, it

would likely ruin the great aileron feel of these planes.



Vince

========================http://www.matronics.com/Navigator?Rocket-List[/url]

_sp; -->   	  Quote: 	
		  [b]

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ernest(at)flmitigation.co
Guest

Posted: Thu Nov 15, 2012 11:04 am Post subject: speed tape

Thanks, great information, I will try it.

Ernest

From:  Rob Ray <smokyray(at)rocketmail.com (smokyray(at)rocketmail.com)>

Reply-To:  <rocket-list(at)matronics.com (rocket-list(at)matronics.com)>

Date:  Thursday, November 15, 2012 1:23 PM

To:  <rocket-list(at)matronics.com (rocket-list(at)matronics.com)>

Subject:  Re: speed tape

Ernest,

  I have tried both Speed tape and Vortelator tape on my RV4 with very little noticeable gain. I'm not a speed freak but really appreciate efficiency in any aircraft.  I am actually more interested in capability at both ends of the speed spectrum and high efficiency in max range cruise flight. That said...

I consulted a Aero Geek bro of mine and he suggested several things I attempt for drag reduction. (None of which involved James cowlings, wheel-pants or plenums) After installing his improvements on my HR2 I noticed a 10-15 Knot increase in cruise speed at WOT. 

Here they are:

1. Wing-Fuselage fairing, large tapered trailing edge-fuselage fairing. (Also helped my RV4). 

2. Filling in and smoothing all control surface "end holes" including Elevator at both ends (My HR2 has RV4 tail feathers, these are the voids at  the ends of the control surface that are hollow) I simply removed them, filled with foam, sanded flush, painted and rebalanced. 

3. Closing propeller/spinner gap. (I used bicycle inner-tube rubber on the inside of my polished Cessna 310 spinner, cut to fit around prop blade and RTV'd in place. 

4. Installed Van's Pressure recovery wheel pants over my larger 380X150X5 tires and paid close attention to how the pant fit around the tire. I still have 4" ground clearance at the rear of the pant in level flight attitude but actually noticed a 5 knot immediate gain over the previous James Pants and they work great on my 1800' turf strip. 

5. Re-rigged all my control surfaces to be aligned inflight with wing tip trailing edge/flap with a 2 degree reflex. (Hey, it works on the Maule and the RV10!) 

All this gave my LyCon IO540 C4B5 GAMI Injected EI electronic ignition equipped HR2 the capability to cruise at 180 KTAS at 11,500 (at) 9.5  GPH LOP. 19"/2700 (WOT) produces just under 225 KTAS at 11,500' at 15.5 GPH LOP, caked mud, grass and soybeans on tailwheel cables notwithstanding!

Hope that helps!

V/R

Smokey

PS: I also installed the above mentioned improvements on my 150HP RVX Hybrid. At S.L. WOT 28"/2800 RPM it produces 177KIAS and 175 KTAS at WOT (at)11,500' Not bad for 1/2 the HP of my HR2!

--- On Thu, 11/15/12, Ernest Hale <ernest(at)flmitigation.com (ernest(at)flmitigation.com)> wrote:

 	  Quote: 	

From: Ernest Hale <ernest(at)flmitigation.com (ernest(at)flmitigation.com)>

Subject: Re: speed tape

To: rocket-list(at)matronics.com (rocket-list(at)matronics.com)

Date: Thursday, November 15, 2012, 7:01 AM

--> Rocket-List message posted by: Ernest Hale <[url=/mc/compose?to=ernest(at)flmitigation.com]ernest(at)flmitigation.com[/url]>

Thanks for the advice, would rather learn on here than in the air.

Ernest

On 11/15/12 9:49 AM, "Vince Frazier" <[url=/mc/compose?to=vincefrazier(at)gmail.com]vincefrazier(at)gmail.com[/url]> wrote:

 	  Quote: 	
		  --> Rocket-List message posted by: Vince Frazier <[url=/mc/compose?to=vincefrazier(at)gmail.com]vincefrazier(at)gmail.com[/url]>

Ernest,

If I recall correctly, putting speed tape on RV ailerons was rejected

by Van.  Even if you could figure out how to keep it in the slot, it

would likely ruin the great aileron feel of these planes.

Vince

========================httpbsp;                        -Matt Dralle, List Admin.nbsp; --> http://www.matronics.com/Navigator?Rocket-List

_sp; --> 

 	  Quote: 	

ic.com

w.buildersbooks.com

thelp.com

ronics.com/contribution

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com

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smokyray(at)rocketmail.co
Guest

Posted: Thu Nov 15, 2012 11:45 am Post subject: speed tape

No worries sir 



Check out these threads for the wing intersection fairing. The last entry has photos and a good writeup.



http://www.vansairforce.com/community/showthread.php?t=59131



Here is some more Aero stuff to consider from Dave Anders amazing RV4 conversion written several years ago but still very applicable:



Drag Producers:

1) Bumps

nav lights

gas caps - act as spoilers

things in high pressure areas - i.e. bottom of wing

hinges (more about this later)

Tie down rings

2) Protrusions

outside on airframe - Antennas!

inside the cowl

components with cylindrical cross section = increased

drag coefficient.

~ 5Xâ€™s the drag coeff. of a turbulent airfoil

~ 50Xâ€™s the drag coeff. of a laminar airfoil

What can you do?

1) eliminate - put them inside the wing tips

(Whip antenna (at) 300 mph takes 3+ hp)

2) fairings - reduce drag up to 90%

3) sweep angle - 60 degrees reduces drag up to 85%

B) How much faster will you go? What is the biggest improvement?

1) The same change will produce different results on different planes. The change depends on:

a) The percentage of the total A/C drag.

(Putting retractable gear on a tumbleweed wouldnâ€™t decrease itâ€™s total drag much.)

b) speed of the plane to begin with.

i.e fairing a rotary beacon

100 Kts = .1 Kt

150 = .6

200 = 2.0

250 = 5.5



Different shapes with Relative drag:



Same cross sectional area in lbs

at the same velocity:

Flat plate 1.0

Cylinder .95

Half sphere forward .35

Half sphere backward 1.5

Rounded cylinder .25

Streamlined body .04

Streamlined body with .035

pressure recovery

Wire .9



Where to start?

A) walk around your plane and make a list of things to improve

B) remove the cowl and take a close look.

Cooling Drag

A) NACA (National Advisory Committee for Aeronautics)

30 to 46% of total aircraft drag. ~ 5% is possible in a well designed system.

B) Formula 1 ~ 0%

C) Excrescence drag - drag from gaps, holes, seams and exits

D) Poor baffling can produce > 50% of the excessive cooling drag.

All garlock seals leak.

Propeller - Inlet - Cowl relationship

1) propeller thrust distribution for inlet location.

2) boundary layer thickness at back edge of spinner and shank of the propeller.

3) differential pressure across inlet.

4) reverse flow on standard inlets.

5) prop extension to decrease flat plate area.

Inlet (stagnation inlet)

1) shape - round = smallest surface area/volume

easiest to provide best seal to plenum.

2) size - calculated from mass flow required for BTU from engine chart.

Mass flow = area X velocity X plenum efficiency

Over-sized inlets velocity resulting in pressure thus cowl drag around the inlets.

3) round lip edge to decrease inlet stall and reduce inlet drag

Plenum design

1) Uses Bernoulliâ€™s Law:

volume = velocity = pressure cubed



2) Greater ô€‚p across the cylinders carries off more BTU.

3) diffuser can diverge 5ô€€¨/side Â± (air flow remains attached due to Velocity and pressure)

4) A = area of inlet (calculated by mass flow requirement)

A = area at the rear of the effect diffuser

A = area over the cylinder and head, A area = A area

5) slowing the free stream velocity 10 - 40% Cooling drag losses.

6) there should be no sharp bends or edges to minimize flow separation.

Outlet - starts under the cylinders

1) area as small as possible to re-accelerate the air to free stream condition to drag.

2) Convergence zone leads to exit fuselage/firewall airfoil rounded gentle curved sides should be ~ 35 deg.

3) Shape - NACA studies

- straight sided rectangular shallow angle converging ramp

- ramp as parallel to free stream flow as possible at end

- width to depth ratio of ramp

a) 7 to 1 for cooling systems

b) 1 to 1 for exhausts (augmenter)

4) inlet to outlet ratio: whatâ€™s recommended, what works & why.

a) stock Vanâ€™s: RV4 ratio ~ 39sqâ€ X 60sqâ€ = 150%

RV6 ratio ~ 44sqâ€ X 56sqâ€ = 127%



Designed for full throttle climbs at 90-100 mph

Results = increased drag at higher speeds

b) what works better:

Inlet 34sq" ( decreased To 30sq" no change)

Outlet 26sq" (excludes exhaust area)

Ratio 76%, could be smaller w/same ratio, CHTâ€™s 350ô€€¨ max

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