X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2606962 for flyrotary@lancaironline.net; Thu, 20 Dec 2007 11:26:20 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([24.74.103.61]) by cdptpa-omta05.mail.rr.com with SMTP id <20071220162539.GKUL26118.cdptpa-omta05.mail.rr.com@edward2> for ; Thu, 20 Dec 2007 16:25:39 +0000 Message-ID: <003901c84324$fd228240$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Supercharging Date: Thu, 20 Dec 2007 11:25:52 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0036_01C842FB.1409A4E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0036_01C842FB.1409A4E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Interesting find, David. =20 I must admit after seeing all of those squirrel cage fan "electric = superchargers" advertised for $59.99 on E bay and else where back a few = years ago (and perhaps even today) - I was very skeptical of what I = would see here. I also could not find any technical specifications or = compressor map on the website - and that does not lessen my skeptical = feeling.=20 However, from the forum "testimonials" in which several folks have = dynoed the results as well as collected other parameters, I must admit = it appears there is some validity to the claims or else they are somehow = fooling a lot of folks {:>). It appears to take between 700 and 1100 watts of power from what data I = could find. So Power =3D Current*Voltage. The current would then I =3D = Power/Voltage =3D 1100/12 =3D 91 amps, or 700/12 =3D 58 amps. So the = current draw may depend on the model but would appear to range from 58 - = 91 amps or around 1 - 1.4 HP. So a fully charged battery would probably = power it for 5-10 minutes - perhaps longer, you could get more precise = interval by looking up the Reserve Capacity of your battery.=20 I must admit that for the price it is tempting just to get one and play = with it - However, I have not seen anywhere mention of its weight. From = the electric motors I have seen, - a 1 - 1.4HP electric motor can be = huge and heavy. Now this is surely a smaller/lighter weight motor than = those heavy weighs. I forget my DC motor types, but as best I recall = there is one referred to as a series winding that simply keeps spinning = faster (and drawing lots of current) until it meets its load limit (or = flies apart). But again no specifications that I could find. So putting aside my skepticism (for the moment) I would think for = aircraft use you would probably want a second battery you could dedicate = to powering the superchargers electric motor for a several minutes. = Hummm, where did I put that second battery case, I took out of my = aircraft.=20 I would certainly want to know how long the motor could stand the load = and heat. It does not appear this is meant for sustained boost, just = for getting your Mustang from 0-60 quickly then off the boost. But, = having 30 more HP for take off and initial climbout for 3-5 minutes = could be nice to have. Then the next question is how much effect it has = on the air flow to your engine when it is not under power. Eliminating = the need for hot exhaust gas and water coolant lines would be also be a = plus. Could not tell whether it required any tie in to the engines = lubrication system - one would presume so, but there was a turbocharger = sold for a while that had its own oil reservoir. And of course what does = it weigh? Still for $100 it might be interesting to experiment with. But, I'll = wait a bit - no mention of problems on the site, but also no mention of = life cycles or hours of run time. Still a bit skeptical, when I don't = see any specifications on a website, but willing to suspend it for a = while {:>) Ed ----- Original Message -----=20 From: David Leonard=20 To: Rotary motors in aircraft=20 Sent: Thursday, December 20, 2007 9:06 AM Subject: [FlyRotary] Re: Supercharging Google place this ad for electric superchargers on the last post. At = least it is designed for an engine.. http://www.electricsupercharger.net/ Dave Leonard On Dec 20, 2007 6:02 AM, Thomas Jakits = wrote: Here a another interesting bit on the screw type charger "wars": http://www.svtsnake.com/forum/archive/index.php/t-1387.html=20 Obviously one must do his homework before deciding on one.=20 However the design seems superior to the roots anyway .... TJ On Dec 19, 2007 11:15 PM, Ed Anderson < eanderson@carolina.rr.com> = wrote: ----- Original Message -----=20 From: "Charlie England" To: "Rotary motors in aircraft" =20 Sent: Wednesday, December 19, 2007 10:47 PM Subject: [FlyRotary] Re: Supercharging > Ernest Christley wrote: >> David Leonard wrote: >>>> 6000RPM is about the speed that commercial leaf blowers use. = The >>>> blowers just happen to be about the same size as an engine = housing. A >>>> conservative blower will easily deliver 600 CFM at 150MPH. >>>> =20 >>> >>> >>> Somehow we are going to have to connect the blower to the = drive=20 >>> chain. That >>> is either going to be a belt (with pullys we can size however = we want) or >>> some sort of gear. Either way, everyone will have a blower = running=20 >>> the rpm >>> they need, no advantage (or disadvantage) to the rotary = running at=20 >>> 6000 rpm. >>> >>> >>> =20 >>=20 >> What if you replace the flywheel with the fan from the blower? = No=20 >> gears. No belts. No chains. No heavy mounting to support any = of=20 >> them. The advantage of the rotary running at 6000 RPM is that = we don't=20 >> have to pull the power off and transfer it over to a different=20 >> structure. We can mount the blower as an integral part of the = drive chain. >>> =20 >>>> We don't >>>> usually want a LOT of boost in an airplane, since that will = impact >>>> reliability, but how much is a LOT? >>>> =20 >>> >>> >>> True, not "a lot" by race standards, but if you just turbo = normalize you >>> WILL be using a lot of boost (by OEM standards) when above = 10000'. I=20 >>> could >>> easily max out my stock turbo at 14000. >> More power is always more better, but what deal with the devil = do you=20 >> have to make to get it? My project can't handle the weight of = a turbo=20 >> or a supercharger, and I personally don't want to deal with the = >> complications of either. So I back off, accept less power as = the=20 >> penalty for doing less work. Can I get 10Hp for a couple = pounds on the=20 >> nose and a few more feet of intake plumbing? The answers we've = come up=20 >> with so far say that it is a definite 'maybe', with a solid = dose of 'it=20 >> depends'. Maybe I won't be able to completely normalize, but I = think I=20 >> should be able to increase my service ceiling. An alternate = air intake=20 >> will enable me to test to see just how much it increases. >>=20 >> --=20 >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: =20 >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >>=20 >>=20 > A 'sanity check' (of the concept) might be in order. >=20 > How big is the 'fan' in the leaf blower (diameter & thickness)? >=20 > How big is the 'fan' in a typical turbo for the rotary? >=20 > Is it likely that the 'fan' from the leaf blower can move as = much air=20 > against the same back pressure turning 6k rpm as the turbo = turning 100k rpm? >=20 > (A P-port will *reduce* weight as it adds HP. :-) ) >=20 > Charlie >=20 =20 Hi Charlie,=20 Flew past your place on Monday heading back from Louisiana, gave a = radio call but got no response and didn't have time to stop for a visit. Regarding your suggestion/question. Part of the problem is that = the engine will always displace the same cubic inches per revolution. = Therefore, there are only two ways to get more power per revolution - = increase the density of the air or provide more oxidizer through a = chemical process such as Nitrous oxide. You simply can not force the = engine to produce more power per rev without doing one of the two - or = both. =20 A turbo compressor or supercharger has to compress (increase the = density of the air) without letting the higher pressure air (as a result = of increased density) flow backwards past the pump impellers from the = high pressure area to the low pressure area. The roots type blower does = this by acting as a positive displacement pump it self whereas the = centrifugal compressor simply uses the superfast spinning blades to beat = the air molecules from the low pressure area (intake) to the high = pressure area (manifold) and with such close tolerances that the air = molecules have difficulty overcoming the momentum of the air and trying = to flow back from the high pressure area against the spinning blades. So the reason the turbo and supercharger increase power for a = given rpm over an N/A engine is they increase the density of the air = not the velocity or volume - those are just side effects. The flow rate = will in fact appear to increase because the non compressed flow will = flow faster into the compressor's intake as the increase in density = after the compressor must come from additional airflow into the = compressor. However, the engine itself is still flowing the same cubic = feet/sec its displacement of course does not change - its just that its = combustion chamber is now packed with more air due to the higher = density. I certainly hope the experiment proves worthwhile - but, I must = admit I can not see how it is going to significantly increase power. = Whether the power addition is worth the effort will depend on how much = effort it requires for the gain. Just my 0.02 Ed --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net ------=_NextPart_000_0036_01C842FB.1409A4E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Interesting find, David.   =
 
I must admit after seeing all of those squirrel=20 cage fan  "electric superchargers" advertised for $59.99 on E = bay and=20 else where back a few years ago (and perhaps even today)  - I was = very=20 skeptical of what I would see here.  I also could not find any = technical=20 specifications or compressor map on the website - and that does not = lessen my=20 skeptical feeling. 
 
 However, from the forum "testimonials" in = which=20 several folks have dynoed the results as well as collected other = parameters, I=20 must admit it appears there is some validity to the claims or else they = are=20 somehow fooling a lot of folks {:>).
 
It appears to take between 700 and 1100 watts of = power=20 from what data I could find.  So Power =3D Current*Voltage.  = The current=20 would then I =3D Power/Voltage =3D 1100/12 =3D 91 amps, or 700/12 =3D 58 = amps.  So=20 the current draw may depend on the model but would appear to range from = 58 - 91=20 amps or around 1 - 1.4 HP.  So a fully charged battery would = probably power=20 it for 5-10 minutes - perhaps longer, you could get more precise = interval by=20 looking up the Reserve Capacity of your battery.
 
I must admit that for the price it is tempting = just to get=20 one and play with it - However, I have not seen anywhere mention of its=20 weight.  From the electric motors I have seen,  - a  1 - = 1.4HP=20 electric motor can be huge and heavy.  Now this is=20 surely  a smaller/lighter weight motor than those heavy = weighs.  I=20 forget my DC motor types, but as best I recall there is one referred to = as a=20 series winding that simply keeps spinning faster (and drawing lots of = current)=20 until it meets its load limit (or flies apart).  But again no=20 specifications that I could find.
 
So putting aside my skepticism (for the moment) =  I=20 would think for aircraft use you would probably want a second battery = you could=20 dedicate to powering the superchargers electric motor for a several=20 minutes.  Hummm, where did I put that second battery case, I took = out of my=20 aircraft. 
 
I would certainly want to know how long the = motor could=20 stand the load and heat.  It does not appear this is meant for = sustained=20 boost, just for getting your Mustang from 0-60 quickly then off the = boost. =20 But, having 30 more HP for take off and initial climbout for 3-5 minutes = could=20 be nice to have.  Then the next question is how much effect it has = on the=20 air flow to your engine when it is not under power.  Eliminating = the need=20 for hot exhaust gas and water coolant lines would be also be a = plus.  Could=20 not tell whether it required any tie in to the engines lubrication = system - one=20 would presume so, but there was a turbocharger sold for a while that had = its own=20 oil reservoir. And of course what does it weigh?
 
 
Still for  $100 it might be interesting to = experiment=20 with.  But, I'll wait a bit - no mention of problems on the site, = but also=20 no mention of life cycles or hours of run time.  Still a bit = skeptical,=20 when I don't see any specifications on a website, but willing to suspend = it for=20 a while {:>)
 
Ed
----- Original Message -----
From:=20 David=20 Leonard
Sent: Thursday, December 20, = 2007 9:06=20 AM
Subject: [FlyRotary] Re:=20 Supercharging

Google place this ad for electric superchargers on the = last=20 post.  At least it is designed for an engine..

http://www.electricsupercha= rger.net/

Dave=20 Leonard

On Dec 20, 2007 6:02 AM, Thomas Jakits <rotary.thjakits@gmail.com&g= t;=20 wrote:
Here=20 a another interesting bit on the screw type charger = "wars":

http://www.svtsnake.com/forum/archive/index.php/t-1387.ht= ml=20

Obviously one must do his homework before deciding on = one.=20
However the design seems superior to the roots anyway ....


TJ

On Dec 19, 2007 11:15 PM, Ed Anderson < = eanderson@carolina.rr.com> wrote:
 
----- Original Message -----
From: "Charlie England" <ceengland@bellsouth.net>
To: "Rotary motors in aircraft" = <flyrotary@lancaironline.net>
Sent: Wednesday, December 19, 2007 10:47=20 PM
Subject: [FlyRotary] Re:=20 Supercharging

> Ernest Christley wrote:
>> = David=20 Leonard wrote:
>>>> 6000RPM is about the speed that = commercial leaf blowers use.  The
>>>> blowers = just=20 happen to be about the same size as an engine housing. =20 A
>>>> conservative blower will easily deliver 600 = CFM at=20 150MPH.
>>>>    =20
>>>
>>>
>>> Somehow we are = going to=20 have to connect the blower to the drive
>>> = chain. =20 That
>>> is either going to be a belt (with pullys we = can size=20 however we want) or
>>> some sort of gear.  = Either way,=20 everyone will have a blower running
>>> the=20 rpm
>>> they need, no advantage (or disadvantage) to = the=20 rotary running at
>>> 6000=20 rpm.
>>>
>>>
>>>  =20
>>
>> What if you replace the flywheel with = the fan=20 from the blower?  No
>> gears.  No = belts.  No=20 chains.  No heavy mounting to support any of
>> = them. =20 The advantage of the rotary running at 6000 RPM is that we don't=20
>> have to pull the power off and transfer it over to a=20 different
>> structure.  We can mount the blower as = an=20 integral part of the drive chain.
>>> =20
>>>>  We don't
>>>> usually = want a LOT=20 of boost in an airplane, since that will = impact
>>>>=20 reliability, but how much is a=20 LOT?
>>>>    =20
>>>
>>>
>>> True, not "a lot" = by race=20 standards, but if you just turbo normalize you
>>> = WILL be=20 using a lot of boost (by OEM standards) when above 10000'.  I =
>>> could
>>> easily max out my stock = turbo at=20 14000.
>> More power is always more better, but what deal = with=20 the devil do you
>> have to make to get it?  My = project=20 can't handle the weight of a turbo
>> or a supercharger, = and I=20 personally don't want to deal with the
>> complications = of=20 either.  So I back off, accept less power as the
>> = penalty=20 for doing less work.  Can I get 10Hp for a couple pounds on = the=20
>> nose and a few more feet of intake plumbing?  = The=20 answers we've come up
>> with so far say that it is a = definite=20 'maybe', with a solid dose of 'it
>> depends'.  = Maybe I=20 won't be able to completely normalize, but I think I
>> = should=20 be able to increase my service ceiling.  An alternate air = intake=20
>> will enable me to test to see just how much it=20 increases.
>>
>> --
>> = Homepage: =20 http://www.flyrotary.com/
>> Archive and UnSub:  
>> = http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>
>>
> A 'sanity check' (of the = concept)=20 might be in order.
>
> How big is the 'fan' in the = leaf=20 blower (diameter & thickness)?
>
> How big is the = 'fan'=20 in a typical turbo for the rotary?
>
> Is it likely = that the=20 'fan' from the leaf blower can move as much air
> against = the same=20 back pressure turning 6k rpm as the turbo turning 100k = rpm?
>=20
> (A P-port will *reduce* weight as it adds HP. :-) = )
>=20
> Charlie
> 
 
 Hi = Charlie,=20
 
Flew past your place on Monday heading = back from=20 Louisiana, gave a radio call but got no response and didn't have = time to=20 stop for a visit.
 
Regarding your suggestion/question.  = Part of=20 the problem is that the engine will always displace the same cubic = inches=20 per revolution.  Therefore, there are only two ways to = get=20 more power per revolution - increase the density of the air = or=20 provide more oxidizer through a chemical process such as Nitrous=20 oxide.  You simply can not force the engine to produce more = power per=20 rev without doing one of the two - or both. 
 
A turbo compressor or supercharger has to = compress=20 (increase the density of the air) without letting the higher = pressure air=20 (as a result of increased density) flow backwards past the=20 pump impellers   from the high pressure area to the = low=20 pressure area.  The roots type blower does this by acting as = a=20 positive displacement pump it self whereas the centrifugal = compressor=20 simply uses the superfast spinning blades to beat the air = molecules from=20 the low pressure area (intake) to the high pressure area = (manifold) and=20 with such close tolerances that the air molecules have difficulty=20 overcoming the momentum of the air and trying to flow back from = the high=20 pressure area against the spinning blades.
 
So the reason the turbo and supercharger = increase=20 power for a given rpm over an N/A engine is  they increase = the=20 density of the air not the velocity or volume - those are just = side=20 effects.  The flow rate will in fact appear to increase = because the=20 non compressed flow will flow faster into the compressor's intake = as the=20 increase in density after the compressor  must come from = additional=20 airflow into the compressor.  However, the engine itself is = still=20 flowing the same cubic feet/sec its displacement of course does = not change=20  - its just that its combustion chamber is now packed with = more air=20 due to the higher density.
 
 I certainly hope the experiment = proves=20 worthwhile - but, I must admit I can not see how it is going to=20 significantly increase power.  Whether the power addition is = worth=20 the effort will depend on how much effort it requires for the=20 gain.
 
Just my 0.02
 
Ed
 
 
 
 
 
 

=


--
David Leonard

Turbo Rotary RV-6 = N4VY
http://N4VY.RotaryRoster.nethttp://RotaryRoster.net=20 ------=_NextPart_000_0036_01C842FB.1409A4E0--