Kent Paser

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BJC

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I just saw a bump on an old thread that referenced Kent Paser's Speed with Economy book, and it reminded me of a question.

Has anyone validated his claims on fuel consumption reduction from "anti-flow reversion nozzles?"

A few years ago I found that they were being used on some high RPM Honda race car engines, but have not seen anything else. If they work as claimed, it seems that they would be widely used.

Thanks,


BJC


 

addaon

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I haven't seen any external confirmation, but one of the nice points of his book is that all of his changes are backed by measurement... I'd lean towards strongly believing his claims, although how generalizable they are is less clear.
 

TFF

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Its been around car hot rodding a long time. It seems that it works best when all the other engine parts are set to perform at the same resonance. 50-50 shot of helping if you just bolt it on from car dyno tests I have seen.
 

plncraze

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Get Paser's book "Speed with Economy" and look at the old issues of Sport Aviation that have the LBF races in them. That will give you an idea of what he has achieved over the years.
 

rv6ejguy

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Get Paser's book "Speed with Economy" and look at the old issues of Sport Aviation that have the LBF races in them. That will give you an idea of what he has achieved over the years.
Guys like Kent Paser and Dave Anders have shown just what you can do with some smarts, experimentation/ flight testing and tweaking. Both amazing guys. My hat is off to people like this.
 

DangerZone

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I just saw a bump on an old thread that referenced Kent Paser's Speed with Economy book, and it reminded me of a question.

Has anyone validated his claims on fuel consumption reduction from "anti-flow reversion nozzles?"

A few years ago I found that they were being used on some high RPM Honda race car engines, but have not seen anything else. If they work as claimed, it seems that they would be widely used.

Thanks,


BJC


Race cars&bikes in the 1980s used a lot of information and experience from experimental aircraft development, and vice versa. I tried to get some more info on this author but Amazon does not have the option of 'See inside' to show more contents. This article online is about some aspects of the book Speed with Economy:

http://www.eaa393.org/Presentations/ScotS_rev_SwEconomyKentPaser2006.pdf

It sounds interesting because this is exactly what producers of enhanced performance aftermarket parts have been doing in motorbikes. For example, Akrapovic who is the best bike exhaust aftermarket system manufacturer in the World uses the principles of fluidics to achieve those valuable +HP increases. Turbocharged engines also need streamlined exhaust flows to achieve better performance, there's a lot to gain from well designed engine fluid inlets and outlets.

I would love to read this book in .pdf form if anyone has it, and I would buy it online over Amazon if it contains good information about aircraft efficiency increase. The book is written more than 20 years ago, I doubt more recent information about fluid flow or inlet/outlet economy would be there. There is a good chance valuable info might be contained about specific aircrft types yet we have to be aware that more than 20 years of improvement has passed since then. Just to point out the difference between 1989-1994 and 2010-2015, the motorbike race normally aspirated engines around 1000ccm went from 150HP to 250HP just because of a better design, and with the modern electronics the consumption went down some 30%. This is the result of good engineering and applying valid principles or experience in the field. In other words, it is possible that Kent Paser might have been ahead of his time when it comes to experimental aircraft efficiency and economy increase.

Taking a look at aircraft like the AR-5, Polen Special, Nemesis aircraft and some others, we could notice there is a lot one could do to achieve better performance, efficiency or economy. Changing oil line 90 degree angles from square to turned reduces engine temperature&consumption and increases engine power&economy. Equal flow exhaust flows with well designed mufflers can sometimes lead to increases of 20% and a good ram air inlet can reduce consumption and cylinder head temperature as much as 30%. Arnold showed how a streamlined body increases aircraft speed and efficiency so why not apply all this knowledge to a homebuilt design?

Anyway, I'm curios about the book contents so if anyone has it in .pdf form please be so kind to let me take a peek inside and see whether it would be good to have it on my shelf.
 

BJC

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The book is worth reading, even though it is old. Kent took a stock MM II with a boxy cowling and the standard canopy, and increased the top speed at altitude by 64 MPH. Some HP improvements, but mostly through aero improvements. The EAA sells it.

The anti flow reversal cones he used did not increase his speed any, but did redice the fuel flow at the same speed by approximately 1 GPH. He is credible, but some people have questioned his data. That is why I asked if anyone here has used them and can validate the results.


BJC
 

DangerZone

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The book is worth reading, even though it is old. Kent took a stock MM II with a boxy cowling and the standard canopy, and increased the top speed at altitude by 64 MPH. Some HP improvements, but mostly through aero improvements. The EAA sells it.

The anti flow reversal cones he used did not increase his speed any, but did redice the fuel flow at the same speed by approximately 1 GPH. He is credible, but some people have questioned his data. That is why I asked if anyone here has used them and can validate the results.


BJC
Thanks for the info, can't help with the validation of data but I'll try to get a copy to see if there's anything interesting for myself.
 

bmcj

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I have the book too. It's been awhile since I've read it... I'll have to pull it out and review.
 

StarJar

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Looking at the anti-flow-reversion drawing, I think it would give high pressure gas a place to occupy, durring peak gas flow, and then re-enter the stream when the pressure/flow decreases, durring each cycle.
A claimed one gallon per hour difference sure makes it interesting to try.
 
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