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dmac11(at)telus.net
Guest

Posted: Fri May 25, 2007 10:33 am Post subject: propeller optimization

I spoke with a gent at Warp Drive who explained that with the short blade's  used on the europa, the blade pitch angle needed for higher speeds can be  greater than optimal causing turbulance near the tips.  

He told me they can modify the blade near the tips to alleviate this problem  and pick up 5 or 10 kts. He also said it would be better for the europa if one  used the 912 gear ratio (2.27:1) rather than the 914( 2.43:1).  

Has anyone tried the constantspeed blade planeform from Warp Drive? or used  the 912 gear ratio on the 914? if so was performance improved?  

Dwayne McAllister   

dmac11(at)telus.net

    [quote][b]

rehn(at)rockisland.com
Guest

Posted: Fri May 25, 2007 11:26 am Post subject: propeller optimization

Dwayne  

   

I would talk to the folks at Airmaster; they did extensive testing for their prop using the Europa as the test platform! They seem like pretty smart folks and worked with Warp Drive during the development. The Mono wheel may have some blade length compromises due to the ground clearance but I don’t know. I don’t think Rotax would recommend switching gears around between 912 and 914. I sure like my Airmaster, its worked great for 6 years.  

   

Jerry  

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Dwayne McAllister

 Sent: Friday, May 25, 2007 11:32 AM

 To: Europa-List(at)matronics.com

 Subject: propeller optimization  

  

     

I spoke with a gent at Warp Drive who explained that with the short blade's used on the europa, the blade pitch angle needed for higher speeds can be greater than optimal causing turbulance near the tips.   

He told me they can modify the blade near the tips to alleviate this problem and pick up 5 or 10 kts. He also said it would be better for the europa if one used the 912 gear ratio (2.27:1) rather than the 914( 2.43:1).   

Has anyone tried the constantspeed blade planeform from Warp Drive? or used the 912 gear ratio on the 914? if so was performance improved?   

Dwayne McAllister   

dmac11(at)telus.net  

   	  Quote: 	
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        [quote][b]

dmac11(at)telus.net
Guest

Posted: Sat May 26, 2007 8:33 am Post subject: propeller optimization

Hello Jerry,

  Perhaps you are right. The blades on my air master 308 are from lockwood and 

were warp drive blades that were installed in the airmaster hub. Are they 

different from the blades supplied from airmaster? Perhaps all the blades 

supplied by airmaster have the "constant speed blade planform" I don't know. It 

is a $55 per blade option.

  Rotec in vernon has told me there is no probem using the 912 gears on the 

914, my question was is it really worth any performace advantage? It would be 

interesting to know that before changing gears of course.

  Did you remove your engine from the plane and take it to Vernon or just the 

gear drive?

  I would like to see a photo of your plane if you have one handy,is the panel 

all electric or has it a vac pump? Mine is all electric. It was a nice surprise 

meeting  you, because I knew of your name from the internet. 

  Are you up and flying now? me to much work going on but come july and august 

will be free.                                  

                                 Have a great day, Dwayne

Quoting Jerry Rehn <rehn(at)rockisland.com>:



 	  Quote: 	
		   Dwayne

 

  

 

 I would talk to the folks at Airmaster; they did extensive testing for their

 prop using the Europa as the test platform! They seem like pretty smart

 folks and worked with Warp Drive during the development. The Mono wheel may

 have some blade length compromises due to the ground clearance but I don't

 know. I don't think Rotax would recommend switching gears around between 912

 and 914. I sure like my Airmaster, its worked great for 6 years.

 

  

 

 Jerry

 

  

 

   _____  

 

 From: owner-europa-list-server(at)matronics.com

 [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Dwayne

 McAllister

 Sent: Friday, May 25, 2007 11:32 AM

 To: Europa-List(at)matronics.com

 Subject: propeller optimization

 

  

 

 I spoke with a gent at Warp Drive who explained that with the short blade's

 used on the europa, the blade pitch angle needed for higher speeds can be

 greater than optimal causing turbulance near the tips. 

 

 He told me they can modify the blade near the tips to alleviate this problem

 and pick up 5 or 10 kts. He also said it would be better for the europa if

 one used the 912 gear ratio (2.27:1) rather than the 914( 2.43:1). 

 

 Has anyone tried the constantspeed blade planeform from Warp Drive? or used

 the 912 gear ratio on the 914? if so was performance improved? 

 

 Dwayne McAllister 

 

 dmac11(at)telus.net

dmac11(at)telus.net
Guest

Posted: Sat May 26, 2007 8:44 am Post subject: propeller optimization

Thanks Jerry, I'll take your advice. Rotax in Canada have told me there  is no problem to use the 912 gears on the 914 but while the man at warp drive said performance would be improved, how much was my question.

Visit -  www.EuropaOwners.org

rampil

Joined: 04 May 2007
Posts: 870

Posted: Sun May 27, 2007 6:53 am Post subject: Re: propeller optimization

Dwayne,

 When you mention the gear ratio of the 912, you are talking about the 

80 HP engine right?



The 912S and 912ULS use 1:243



Ira N224XS

_________________
Ira N224XS

rampil

Joined: 04 May 2007
Posts: 870

Posted: Sun May 27, 2007 6:53 am Post subject: Re: propeller optimization

of course there is a decimal point in the 2.43

_________________
Ira N224XS

dmac11(at)telus.net
Guest

Posted: Sun May 27, 2007 11:37 am Post subject: propeller optimization

Yes Ira the 912 80 hp version comes with 2.27:1 gear ratio, (at) 5800 rpm, prop 

will be 2555 rpm, 912s & 914 use 2.43:1 ratio (at) 5800 rpm, prop will be 2386 rpm.

                                             Regards, Dwayne

fklein(at)orcasonline.com
Guest

Posted: Sun May 27, 2007 2:41 pm Post subject: propeller optimization

Those concerned w/ this topic would be well to question the basic 

performance of the Warp Drive blades. In a series of emails I exchanged 

w/ Airmaster some time ago, they concede that the shortened blades 

needed for the Europa and given the speed ranges in which it flies, 

these blades leave much to be desired.



Fred

A194



..hoping to trial fit wings to CM next week...sigh...

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grahamsingleton(at)btinte
Guest

Posted: Sun May 27, 2007 3:35 pm Post subject: propeller optimization

Fred

Good point. I spoke to the Airmaster guys a few years ago and they told 

me they spent a lot of time looking for the right blades. Warp were far 

from ideal, the design of the prop was for ragwing microlights, but 

nobody else was cooperative. Sad, Arplast would have been ideal but the 

chemistry didn't work so both Arplast and Airmaster lost out. Alain 

Petit, the Arplast boss is a nice guy but his English isn't confident 

and I don't suppose the NZ guys speak much French. What an opportunity 

missed. Wish I had been in the right place a few years earlier!

Graham



Fred Klein wrote:

 	  Quote: 	
		   

 

 Those concerned w/ this topic would be well to question the basic 

 performance of the Warp Drive blades. In a series of emails I exchanged 

 w/ Airmaster some time ago, they concede that the shortened blades 

 needed for the Europa and given the speed ranges in which it flies, 

 these blades leave much to be desired.

 

 Fred

rampil

Joined: 04 May 2007
Posts: 870

Posted: Sun May 27, 2007 4:42 pm Post subject: Re: propeller optimization

The short prop blades are really only for monowheel a/c.

When I ordered my Airmaster system for my trigear, I asked for the

blades to each be 2" longer than the "standard Europa" i.e., monowheel

spec.  It was actually a no-charge ECO since the stock blades are

longer still.



Ira N224XS

_________________
Ira N224XS

fklein(at)orcasonline.com
Guest

Posted: Sun May 27, 2007 9:54 pm Post subject: propeller optimization

On Sunday, May 27, 2007, at 05:42  PM, rampil wrote:

 	  Quote: 	
		  

 The short prop blades are really only for monowheel a/c.

 When I ordered my Airmaster system for my trigear, I asked for the

 blades to each be 2" longer than the "standard Europa" i.e., monowheel

 spec.


	


This is of course a step in the right direction; the fan area that a 

prop generates is one of several important factors in prop performance. 

As Ira says, the Warp Drive blades all come from one mold and are 

simply cut down appropriately to serve various aircraft. One problem as 

I understand it is that much of the twist in the WD blades disappears 

when the diameter is reduced. Another is that since the blade was 

designed for a lower speed range (and perhaps lower rpm at cruise) than 

the Europa flies in, at higher speeds the innermost portions of the 

blade actually generates negative thrust due to the configuration of 

the blade cross section. Both of these issues were raised to me by guys 

who know a lot more about props than I do and warrant some 

consideration. Airmaster confirmed to me as Graham states that the WD 

was simply the best available choice...



Fred

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william(at)wrmills.plus.c
Guest

Posted: Sun May 27, 2007 11:20 pm Post subject: propeller optimization

Fred / Graham,

I believe the ideal combination for a constant speed prop would be a 

Woodcomp hub, Arplast blades and a Smart Avionics controller, for the 

following reasons:  The Woodcomp SR 3000 hub is very well engineered and is 

half the price of the Airmaster, the latest Arplast blades PV55 have a slim 

aerofoil with plenty of twist (hub to tip) to cope with cruise speeds of 120 

/130 Kts (about 24 degs is required) and the Smart Avionics controller is 

very good and extremely reliable.

I am trying to persuade Woodcomp to manufacture 100% composite blades for 

their SR 3000, so that they can build in more twist with a slimmer aerofoil. 

Their current blades have wooden cores with a carbon skin, which makes them 

a bit bulky and limits the amount of twist, because of grain run-out.  They 

also produce a very good leading edge protection.

Regards,

William

---

grahamsingleton(at)btinte
Guest

Posted: Mon May 28, 2007 1:47 am Post subject: propeller optimization

Fred,William Ira

William and everyone

I continue to be puzzled by the Warp Drive prop, which we all know was 

designed for slow microlight A/C. Jerry Davis once pointed out that you 

need less twist at hi speed, which can only mean that the Warp has the 

wrong twist at any speed! (Jerry is UK agent for Arplast)

Thinking for a moment, at the root the blade angle should be nearly 

parallel with the direction of flight. At the tip it will be dependant 

on speed, diameter and rpm, (of the prop) With a VP prop it will only be 

optimised at one particular speed but should be a good compromise for 

the speed range.

I haven't done any sums so more than that I won't say at this point.

Graham



William Mills wrote:

 	  Quote: 	
		   

 <william(at)wrmills.plus.com>

  the latest Arplast blades PV55 have  a slim aerofoil with plenty of 
	


twist (hub to tip) to cope with cruise

 	  Quote: 	
		   speeds of 120 /130 Kts (about 24 degs is required) 

 Regards,

 William

william(at)wrmills.plus.c
Guest

Posted: Mon May 28, 2007 2:48 am Post subject: propeller optimization

Graham et al,

I think you will find, if you do the vector diagrams at intervals along the 

blade, that the faster the forward speed of the A/C, the more twist you need 

in the blades for them to provide lift along the whole length of the blade. 

Hence, the PV50 and 55 have much more twist than the Warp Drive.  At slow 

speeds i.e. at take-off, the inner section of blade will have too much AOA 

but that is better than producing negative lift at high speed (as Fred has 

already pointed out).  The ideal prop would have adjustable blade twist as 

well as variable pitch.

Regards,

William

---

carl(at)flyers.freeserve.
Guest

Posted: Mon May 28, 2007 3:47 am Post subject: propeller optimization

There seems to be a suggestion the Arplast Propeller blades are better 

suited to the Europa than the Warp drive ones (as used in the Airmaster).



Why then is the Airmaster regarded as the better combination - (ie: endorsed 

by the Europa factory.)



There is a perception that price is generally an indication of quality/ 

suitability but in this case that dosent appear to be so.



I understand the Airmaster costs in the region of £4,000 - what is the price 

of a complete Arplast installation for the Europa? I cant find any prices on 

the UK distributors pages.



Carl Pattinson

G-LABS



In need of a VP/ CS prop.



---

TELEDYNMCS(at)aol.com
Guest

Posted: Mon May 28, 2007 4:55 am Post subject: propeller optimization

In a message dated 5/28/2007 2:58:33 AM Eastern Daylight Time,  europa-list(at)matronics.com writes:

  	  Quote: 	
		  Good    point. I spoke to the Airmaster guys a few years ago and they told 

me they    spent a lot of time looking for the right blades. Warp were far 

from    ideal, the design of the prop was for ragwing microlights, but 

nobody else    was cooperative. Sad, Arplast would have been ideal but the 

chemistry    didn't work so both Arplast and Airmaster lost out. Alain 

Petit, the    Arplast boss is a nice guy but his English isn't confident 

and I don't    suppose the NZ guys speak much French. What an opportunity 

missed. Wish I    had been in the right place a few years earlier! 	
  

 Greetings team,

  

 I have it on good authority from Airmaster as of this morning that  they are on schedule to release a new electrically adjustable hub at  Oshkosh this year that uses Sensenich hollow carbon blades. I will be  installing this new arrangement on N245E as soon as it becomes  available.

  

 Regards,

  

 John Lawton

 Dunlap, TN (TN89)

 N245E - Flying

 

  



See what's free at AOL.com. 

  [quote][b]

m.j.gregory(at)talk21.com
Guest

Posted: Mon May 28, 2007 5:58 am Post subject: propeller optimization

Has anyone tried an Elippse propeller on a Europa?  See article

www.batterson.net/EAA499/Issue77_8-13.pdf which makes some interesting

points about propeller design.



Mike



--

davidjoyce(at)doctors.org
Guest

Posted: Mon May 28, 2007 5:59 am Post subject: propeller optimization

William Mills wrote:

 	  Quote: 	
		   Graham et al,

 I think you will find, if you do the vector diagrams at intervals along

the
	


 	  Quote: 	
		   blade, that the faster the forward speed of the A/C, the more twist you

need
	


 	  Quote: 	
		   in the blades for them to provide lift along the whole length of the

blade.
	




William, To an unfulfilled mathematician (one who discovered nurses at a

sensitive stage in his emotional development and got diverted into

medicine!) this was too tempting to ignore. For a 62" diameter prop doing

2300rpm, tip speed 369 kts, I got the following figures for tip angleof

incidence, angle at one third radius out from centre, twist (the 1/3 angle

less the tip angle) and speed of travel. These figures relate simply to the

angles needed to keep up with the airflow. In practice of course an angle of

attack has to be added to produce lift.

              TIP ANGLE     1/3 ANGLE         TWIST            SPEED (Knots)

                   5.7                    16.7                   11.0

36.6

                   9.5                     26.6                   17.1

61

                  14.9                    38.6                   23.7

98

                  18.4                    45.0                   26.6

123

                  21.8                    50.0                   28.2

148

                  26.6                    56.3                   29.7

184

That much nicely confirms your statement, although interestingly enough if

you continue the table the trend for increasing twist goes into reverse,

thus:

                  33.7                     63.4                   29.7

246

                  39.8                     68.2                   28.4

307

                  45.0                      71.6                  26.6

368

This extended bit of table is pretty irrelevant to any Europa, although it

does imply that if we optimised the prop for130 or 140 kts it would be

pretty good for all speeds above. The snag is that  the optimal twist for

say 123 kts is 15 more than you need at 50kts and 10 more than at 60kts. So

a 120 kt prop is going to be bad at getting you off the ground, when at

least half of the blade is likely to either in reverse thrust or stalled

mode - and no doubt this accounts for manufacturers generally optimising

their props on figures below 100kts.

          This situation is also probably highly relevant to the blade cross

section. I don't have any figures for critical angle of attack of different

prop blade sections, but I could imagine that the relatively wide Woodcomp

section might have  a range of perhaps 12 degrees from zero lift to stall

whereas the thin, sharp nosed section of the Arplast and the Warp Drive may

only be half that. If so then the Woodcomp type of section would allow you

to produce some lift (if not maximum) over a significantly greater

proportion of the blade when in 'Too slow for the Twist' mode.

fklein(at)orcasonline.com
Guest

Posted: Mon May 28, 2007 7:15 am Post subject: propeller optimization

Mike...thanks so much for the reference...fascinating article.



Fred



DO NOT ARCHIVE



On Monday, May 28, 2007, at 06:56  AM, Mike Gregory wrote:



 	  Quote: 	
		   

 <m.j.gregory(at)talk21.com>



 Has anyone tried an Elippse propeller on a Europa?  See article

 www.batterson.net/EAA499/Issue77_8-13.pdf which makes some interesting

 points about propeller design.



 Mike




	




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karelvranken(at)hotmail.c
Guest

Posted: Mon May 28, 2007 12:33 pm Post subject: propeller optimization

Graham,

For the first time your explanation doesn't seem very clear to me. I thought 

today there would be a more scientific approach when making a propeller and 

its application. If the Warp blade is so few adequate for the Europa and 

Arplast so good then why don't we have the choice since Airmaster is not the 

manufacturer of the blades?

Best regards,

Karel Vranken.

---

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