Jack Norris' Propeller book

After a couple of years of Jack holding the check I wrote him at Oshkosh, I received his book a couple of months ago. I had meant to write in here and tell everyone how great it is, but somehow it slipped through the cracks.

So, I would like to tell you that this is a wonderful book. It is only a bit mathematical, but gets the idea of how a propeller actually works across better than anything I have read. It is written in a unique style that has the reader imagining he is sitting in the classroom, listening to a charismatic professor tell all. The math that resulted from Jack's investigations helped Paul Lipps design his props, and also produced the Whirlwind RV200 prop.

Also included is another whole book (when you flip it over) called The Logic of Flight. Here Jack tells you how to fly your airplane efficiently.

Jack was the Technical Director for the Voyager 'round the world flight and a lifelong PhD aero engineer, and you can learn a lot from this book.

It is self-published, so send Jack Norris $14.95 plus 2 or 3 bucks for shipping...
Jack Norris
11613 Seminole Circle
Northridge, CA 91326

Have fun,
John

he was an excellent speaker at Bakersfield's EAA meeting last Wed. night.

they invited him back for their Year end Banquet.

He basically kept saying you don't want a prop with a blunt tip-- to a whole room full of people with-- blunt tips. on their Harmon Rockets.

I showed him a prop on a Rocket and we came to the conclusion that on that prop anything over 2550 rpm's wouldn't help any.

So I ran 2550 rpm's in the Rocket Race and I think the next time I run it will be 2750rpm's for a comparsion.

Aren't you the guy that had a smoking fast RV8 in the Rocket Race?

Yes, that was me, thanks!

At Reno this year, I went to the sneak preview of the Thunder over Reno movie. I was sitting with friends, and there was an empty chair next to me. A little old guy came along and asked if he could sit there...turned out to be Jack Norris. I had already read his book and we had a great talk, halfway ignoring the movie. It is amazing how the very smartest guys are also the most humble and likable.

John

mark manda said:

he was an excellent speaker at Bakersfield's EAA meeting last Wed. night.

they invited him back for their Year end Banquet.

He basically kept saying you don't want a prop with a blunt tip-- to a whole room full of people with-- blunt tips. on their Harmon Rockets.

I showed him a prop on a Rocket and we came to the conclusion that on that prop anything over 2550 rpm's wouldn't help any.

So I ran 2550 rpm's in the Rocket Race and I think the next time I run it will be 2750rpm's for a comparsion.

Aren't you the guy that had a smoking fast RV8 in the Rocket Race?

Click to expand...

Hi Mark,

In testing on Ted Rutherford's HR2, the "D" blade Hartzell decreased airspeed by going from 2600 RPM to 2700 RPM. The "J" blade hartzell kept increasing in airspeed up to 2800 RPM. This on a "stock" IO-540.

Another report I received on the "J" blade Hartzell in an F-1 Rocket with a 330 hp IO-540 said that the airspeed decreased by going from 2600 RPM to 2700 RPM.

Test what you have, and find your own RPM "sweet spot" for your race (density) altitude.

I have been reading Jack Norris' Propeller book, also. Jack is a member of the local Chapter 723, and his book is written much like he talks. I have found that Jack is one of the few people that has the insight to understand the data I am getting in my propeller (cruise performance) testing.

Jim Ayers

Jack now has a website with information about his book.

http://www.propellersexplained.com/

John

Sent the Money

I mailed him $20 and I am looking forward to the book. I believe there is so much black magic and B.S. about props that it is agrevating to me. I do not believe I am getting the most out of my system because of prop limitations as far as maximum speed is concerned. I am certainly hoping the book provides some clear answers but I'm not holding my breath. Of course doing something about it will remain a problem. I am convinced that no "off the shelf" prop is going to be the optimum prop for the speed of my airplane - that agitates me - a lot.

Bob Axsom

I have read this book and the useful information can be condensed down into about five pages. The rest of it is written in such a rambling style that its almost painful to read.

I received the book

I received the book in the mail this evening. The author Jack Norris wrote me a sincere encouraging note in the book and I have no doubt that I will learn from the content. The book is 1.25" thick and the pages are 9" high and 6" wide. This will compete for my reading time as I have recently discovered the works of David Baldacci but this is such a big deal that it will command my attention. There is a website http://www.propellersexplained.com.

Bob Axsom

No Pain no gain

rocketbob said:

I have read this book and the useful information can be condensed down into about five pages. The rest of it is written in such a rambling style that its almost painful to read.

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I am in the process of reading the book and I feel your pain. I have not found that it turns me off but the effort to make sure the reader gets the message by repetition is a little painful. Jack says he uses the 2x4 hitting the head approach to drive the message in to the point of easy comprehension so I guess he knows it will be a little agonizing at times. He says he is doing this so everyone who wants to know everything there is to know about propellers without any engineering or math strength will be able to achieve their goal just by reading this book. Every time I go to the bathroom it is required reading (I may name a hemroid "Propeller") but so far I am hooked enough that I continue to read it instead of my David Baldacci novels that are waiting to be read.

Bob Axsom

Bob, I found it helpful to imagine myself in a classroom, with a professor up front who is very enthusiastic, stands up on tiptoe and raises his voice sometimes when he thinks something is important, and is otherwise maybe a little crazy. Kind of like Professor Irwin Cory, but technical.

There is still a lot of content there.

Thanks John

That image works well. The reading is going much better. Jack explains "There are more Pilots than Pros, not sweating at all, it's logical and fair that we expect you to do the adapting to what is necessary, to help the new guys." That is important for a lot of reasons and not just "to help the new guys".

Bob Axsom

Just to set the record straight, my ELIPPSE propeller design predated my having ever spoken with Jack by at least 6 years. I designed my three-blade prop in July of 2002, and received it from Craig Catto in early 2003. My original two-blade, which I used for testing with lots of planes, was built in 1997. After I did the testing of the three-blade, I contacted C.A.F.E. and told them I had a very high efficiency prop and since they were interested in efficiency, perhaps they would like to come to Santa Maria and test it for themselves. They declined (?), but said they would have their propeller expert contact me. This took place when Jack called me several weeks later and we spoke for several hours on the 'phone. I told him about my design philosophy, and he said that the B-G-T, Betz, Goldstein, Theodorsen, was the most efficient shape possible. By this time I had also designed the winning propellers for Tom Aberle and Jeff Lo which demonstrated, before a national venue at the Reno races, that my design was head and shoulders better than what had gone before. My four-blade design, which flies in the face of the "fewer blades is better" philosophy, helped Tom to increase his speed from 221 mph in 2003 with his previous two-blade, to over 252 mph last year! Jack and I have spoken many times over the intervening years, but it was just in the last year that I received a preview of the pages in which he showed that my elliptical (ELIPPSE, get it?) lift distribution actually was better than the B-G-T and which he demonstrates in his book. He now maintains that propellers have an upper efficiency limit of 95%, which makes my claims of 90% or better more palatable to those who maintained that 88%-90% was the upper limit. Nowhere in his book has Jack intentionally or unintentionally claimed that it was his math that set me on the right path. Jack was very generous in giving me complete and total credit for what he terms "...this creative new idea by Paul Lipps of Arroyo Grande California is the new idea for the new Century of Flight." P. I-29-BK II. and that this lift distribution is "...better than the B-G-T ideal!!!" P. I-28-BK II, also "Paul Lipps used his own math to design his props. Full credit goes to him,...". P.I-35-BK II. My thanks to John for accidentally reading something into Jack's book that gave me this opportunity to show the actual chain of events.

what about his other book, "the logic of flight" ? Anybody read that? Comments?

Haven't Read it Yet but...

Haven't Read it Yet but when I ordered the "Propellers..." book "The Logic of Flight" was included in the same cover. It is 172 pages long and it is printed so the the back cover of "Propellers ..." is the front cover of "The Logic of Flight". All of this was covered in the $14.95 price plus 2 or 3 dollars for shipping from Jack Norris himself at 11613 Seminol Circle, Northridge, CA 91326.

Bob Axsom

RVjim said:

Hi Mark,

In testing on Ted Rutherford's HR2, the "D" blade Hartzell decreased airspeed by going from 2600 RPM to 2700 RPM. The "J" blade hartzell kept increasing in airspeed up to 2800 RPM. This on a "stock" IO-540.

Another report I received on the "J" blade Hartzell in an F-1 Rocket with a 330 hp IO-540 said that the airspeed decreased by going from 2600 RPM to 2700 RPM.

Test what you have, and find your own RPM "sweet spot" for your race (density) altitude.

Jim Ayers

Click to expand...

Jim and Bob A.: My prop program and equations show that my design has a very flat efficiency curve vs rpm-speed. I modeled, in my program, the Hartzell that is used on the Sport racers, and I was surprised to find that, according to my program at least, those props peaked in efficiency at about 250 mph and then dropped off from there. Those thin airfoils they use on the metal props are very prone to LE separation, especially when they have bugs or erosion present. Keep your LE as smooth as possible, because the HP losses increase dramatically the farther out on the blade that there is drag present. This is especially true at the tip, where the most losses occur! Remember, HP = drag times radius times rpm divided by a constant. The greater the radius, the greater the drag from dynamic pressure, which is approximately proportional to radius-squared. That's why on my designs, CS or FP, I use a 15% thick airfoil right out to the tip. It has a 100:1 to 150:1 CL/CDp over most of the blade, and performs well out to M0.85 at the tip. At M0.85, CDp is 6-8 times what it is below M0.6! On my biplane FP racer props, if they put in more horsepower or decrease the drag, they get more speed and rpm. And speaking of Jack Norris, when he first called me, he asked me how much a cube of air 100' on a side weighed. I said 7.6*10^-2 lb/cf times (10^2)^3 = 76,000 lb. He was stunned, as he had asked that of many aero types who couldn't come up with the answer and when told the number, expressed dis-belief! It was hard for me to believe that aero types who have to use the air density rho in their calculations couldn't figure that one out!

As I continue to read ...

As I continue to read the book I get more and more interested in the subject. I'm far from "getting it" but the logic is growing on me. I can see for the first time basic mentor like description of the basic underlying science of the function of airplane propellers and relating it to F=MA. This is really important if you are trying to maximize the speed of your airplane. I have long thought that the propeller performance on my airplane was holding down the speed more than anything else and with this growing comprehension of efficient propeller function I know I was right. Down the road a ways I am going to have to make a change perhaps the choice taken will be to have a race prop and a general purpose prop. I may have a hard time explaining that to my wife, it is unlikely I can get her to read "The Book".

Bob Axsom

Bob Axsom said:

Down the road a ways I am going to have to make a change perhaps the choice taken will be to have a race prop and a general purpose prop.
Bob Axsom

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My design will give a somewhat longer takeoff run, but once you get up to about 50-70 mph it takes off like a shot. Tom says it feels like an AB cut in! You will have much better climb performance, especially if you get a three or four blade prop. Now this is for an FP prop. But I have also got MT making a CS prop for a racer, and when we get the performance of that, if it meets expectations, they will be able to make a CS prop that will give RVs a nice takeoff, climb, and speed bump! But keep in mind, if you go from 85% in a Hartzell to 90% in an ELLIPSE, it will only give you 1.9% more speed, just under 4 mph at 200 mph. But if you go from the typical 70% to 80% of the FPs, you will see 8.7% to 4% speed increase! Remember, Tom got 241 mph in 2004 with the three-blade vs 221 in 2003 with the two-blade, at 7.7% less rpm/power. That's an incredible 39.7% efficiency increase!

elippse said:

And speaking of Jack Norris, when he first called me, he asked me how much a cube of air 100' on a side weighed. I said 7.6*10^-2 lb/cf times (10^2)^3 = 76,000 lb. He was stunned, as he had asked that of many aero types who couldn't come up with the answer and when told the number, expressed dis-belief! It was hard for me to believe that aero types who have to use the air density rho in their calculations couldn't figure that one out!

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I'm more surprised to see there are engineers still using English engineering units rather than metric units. <Ducks and runs....>

For back-of-the-envelope calculations I always use the easy-to-remember approximation ~1 kg/m^3. It'd take me a few minutes to convert that to your stones per cubic furlong.

The other interesting thing is that my references say air at S.T.P is ~0.0808 lbm/ft^3.

JimLogajan said:

The other interesting thing is that my references say air at S.T.P is ~0.0808 lbm/ft^3.

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That would give rho as 2.51189exp-3 and several of my references give rho as 2.37689exp-3. von Mises, Theory of flight, Table 2, P.32, 0.002378; Documenta Geigy, sixth edition, ICAO Standard Atmosphere, P.290, 1.2250 kg/m^3. Curious!
Since all engineering units are arbitrary, whether it's the distance from the tip of the King's thumb to the knuckle, the inch, or an unmeasurable distance around the earth, or the length of that bar which is the standard for distance. I use things my mind is familiar with in day-to-day use, units that I can easily visualize. As long as I know that a foot is 0.3048
meter or that a nautical mile is 6076.10333 feet or that c is 983,571,056.4 ft/sec or that there are 788.16 lb-ft/BTU, or that g is 9.80665 m^2/ s^2, 32.17 ft^2/sec^2, it works for me! And whoever said that I'm an engineer? I'm just a curious amateur!

Overseas...

Hi Guys,

I am interested in the Jack Norris book(s). Does any body know if he will ship it overseas? If so how to arrange for this? I guess the 2 or 3 bucks won't fit the shipment bill...

elippse said:

That would give rho as 2.51189exp-3 and several of my references give rho as 2.37689exp-3. von Mises, Theory of flight, Table 2, P.32, 0.002378; Documenta Geigy, sixth edition, ICAO Standard Atmosphere, P.290, 1.2250 kg/m^3. Curious!
Since all engineering units are arbitrary, whether it's the distance from the tip of the King's thumb to the knuckle, the inch, or an unmeasurable distance around the earth, or the length of that bar which is the standard for distance. I use things my mind is familiar with in day-to-day use, units that I can easily visualize. As long as I know that a foot is 0.3048
meter or that a nautical mile is 6076.10333 feet or that c is 983,571,056.4 ft/sec or that there are 788.16 lb-ft/BTU, or that g is 9.80665 m^2/ s^2, 32.17 ft^2/sec^2, it works for me! And whoever said that I'm an engineer? I'm just a curious amateur!

Click to expand...

Am I crazy, or do you have too many distance terms in your acceleration figures? Accel is in distance per time per time, or ft/sec^2

Overseas shipping

phseeya said:

Hi Guys,

I am interested in the Jack Norris book(s). Does any body know if he will ship it overseas? If so how to arrange for this? I guess the 2 or 3 bucks won't fit the shipment bill...

Click to expand...

Hi Duncan,

Jack shipped my book to me in Switzerland, so I'm sure he would ship it to NL.

Regards,
Mickey

Hi Mickey,

Good to know that.
How did you arrange this, did you just send the money or did you send him an email first? I can't find any contact data on the internet.

Duncan, check your PM's. I just sent you one with Jack' s Phone #.
Since international phone calls can be expensive, PM me your city or town and country and I'll get the info for you, as it only costs me 10 cents per minute, if you prefer.

Joe

Thanx..

Hi Joe,

I send you a PM.

Thank you all for your help.
I will post back when I have read the book(s).