# Eastman Jacob's 8-Stage Axial Compressor



## Zipper730 (Aug 27, 2017)

From what I remember reading, Eastman N. Jacobs, a scientist at NACA from 1925-1944, who was an expert in high speed wind-tunnels and airfoil research had planned on building an eight-stage axial-flow turbocharger compressor, which would later be the inspiration for turbojet-engine design.

From what I recall he began the design in 1938: The problem is when the design was first run. I've been doing research and cannot seem to find anything on when it was first run. I know it ended with a catastrophic failure, with him eventually giving up and deciding that it was a fatal-flaw in the design, though another designer named Eugene Wasilewski continuing to pursue the idea a bit longer.


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## wuzak (Aug 28, 2017)

http://www.dtic.mil/dtic/tr/fulltext/u2/b804366.pdf

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## wuzak (Aug 28, 2017)

Better quality version

http://naca.central.cranfield.ac.uk/reports/1943/naca-report-758.pdf

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## wuzak (Aug 28, 2017)

Actually, why does it matter when the Eastman-Jacobs 8 stage compressor was first run?



> Lewis Laboratory's Compressor and Turbine Division conducted research on both centrifugal and axial compressors. John Stanitz applied a relaxation solution to the problem of two-dimensional compressible flow in a centrifugal compressor with straight radial blades - an achievement that established him as an expert in centrifugal compressors.42 However, the compressor staff always had greater enthusiasm for the axial compressor - a legacy of the NACA's first eight stage axial compressor designed by Eastman Jacobs and Eugene Wasielewski in 1938 and tested in 1941. The smaller frontal area of the axial compressor made it more compact and better suited aerodynamically for flight than the more cumbersome centrifugal compressor. However, the greater aerodynamic complexity of the axial compressor presented enormous scientific and engineering challenges. An axial compressor had to be designed so that air moved smoothly across each of the rows of compressor blades. Research initiated in 1944 with the transfer from Langley of work on the Jacobs-Wasielewski eight-stage compressor laid the basis for the laboratory's future achievements in the compressor field. Jacobs and Wasielewski had approached compressor design by applying the theory for an isolated airfoil. This became the standard approach of American designers until the mid-1950s.



https://history.nasa.gov/SP-4306/ch7.htm


I will note that the compressor was not originally intended for use in a gas turbine, but rather as a compressor for piston aero engines.

I am not sure how this approach differed from AA Griffith's work in 1926: An Aerodynamic Theory of Turbine Design


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## Zipper730 (Sep 4, 2017)

wuzak said:


> Actually, why does it matter when the Eastman-Jacobs 8 stage compressor was first run?


Several reasons actually

The design, while originally intended for use as a turbocharger, would inspire engine designers to switch to axial from centrifugal flow
A design starts from an idea in somebody's head, and morphs from a basic idea to a prototype: It doesn't just go from an idea to a workable design in a flash, if it did I'd be famous (probably quite wealthy too), rather than just some guy who procrastinates most of the time.

I was trying to come up with a time-table of gas-turbine development in the United States
I'm surprised it took them from 3 years to the first run-up.


> I will note that the compressor was not originally intended for use in a gas turbine, but rather as a compressor for piston aero engines.


Yes, I even said that in the OP. I am surprised that in the report it was mentioned (which was made in 1942).


> I am not sure how this approach differed from AA Griffith's work in 1926: An Aerodynamic Theory of Turbine Design


Was this available in the States


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## Shortround6 (Sep 4, 2017)

Parsons patented an axial flow compressor in 1884. by 1907 he had built 41 different axial flow compressors including one of 80 stages, , yes eighty stages. They just weren't very good. The Parsons company gave up trying to market them in 1908. 

There were other early axial flow compressors and even industrial gas turbine engines before WW I. The idea/s were there and were in most textbooks.
The problem was getting them to work and that required much better understanding of airflow through the compressor.


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## wuzak (Sep 4, 2017)

Shortround6 said:


> The problem was getting them to work and that required much better understanding of airflow through the compressor.



Which was entirely the point of the NACA 8 stage compressor and the research that underpinned it - to use aerodynamic principles to calculate the performance of an axial compressor and then validate the theory with a test compressor.

Also, incidentally, much the same as the work that Griffiths had doen a dozen or so years earlier. Though I believe Griffith's work was about gas turbines, not just compressors.


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## wuzak (Sep 4, 2017)

Zipper730 said:


> I'm surprised it took them from 3 years to the first run-up.



I think you answered that yourself:



Zipper730 said:


> A design starts from an idea in somebody's head, and morphs from a basic idea to a prototype: It doesn't just go from an idea to a workable design in a flash, if it did I'd be famous (probably quite wealthy too), rather than just some guy who procrastinates most of the time.



But also they had to do the calculations by hand, and no doubt had a few iterations of the design before they settled on the one that was built and tested.




Zipper730 said:


> I was trying to come up with a time-table of gas-turbine development in the United States



Which is OK, but this really wasn't gas turbine development.




Zipper730 said:


> Was this available in the States



I don't see why not.

Based on his paper, Griffith was able to build test engine in 1928, with a single stage axial compressor and turbine.

In the early 1930s working for a government research facility, Griffith designed a counter-rotating multi-stage axial compressor.

About the time the NACA 8-stage compressor was being formulated, Metropolitan Vickers had begun building a gas turbine (turboprop) based on Griffith's original compressor (not the counter rotating one) design. This would be the F.1.

In 1940, after Whittle's jet had flown, the F.1 would be changed to the pure jet F.2. And would lead, eventually, to the Armstrong-Siddeley Sapphire. The Sapphire would be built under licence by Wright as the J-65.


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## Zipper730 (Sep 5, 2017)

Shortround6 said:


> Parsons patented an axial flow compressor in 1884. by 1907 he had built 41 different axial flow compressors including one of 80 stages, , yes eighty stages.


Wow that's a lot of stages


> They just weren't very good. The Parsons company gave up trying to market them in 1908.


Was he marketing them for power-generation or propulsion?


> The problem was getting them to work and that required much better understanding of airflow through the compressor.


I'm surprised they didn't just build a rotor and stator and measure the airflow behind it; then design another rotor and stator, adjust as need be; then build another rotor and stator, and so on until you had what you wanted.


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## Zipper730 (Sep 5, 2017)

wuzak said:


> I think you answered that yourself


Yeah, but I figured it'd take a year or two tops. I have been wrong before 


> But also they had to do the calculations by hand, and no doubt had a few iterations of the design before they settled on the one that was built and tested.


Of course


> Which is OK, but this really wasn't gas turbine development.


That's correct, but it played a role


> I don't see why not.


Why didn't anybody look at it?


> Based on his paper, Griffith was able to build test engine in 1928, with a single stage axial compressor and turbine.
> 
> In the early 1930s working for a government research facility, Griffith designed a counter-rotating multi-stage axial compressor.


Did it have a turbine for every stage?


> About the time the NACA 8-stage compressor was being formulated, Metropolitan Vickers had begun building a gas turbine (turboprop) based on Griffith's original compressor (not the counter rotating one) design. This would be the F.1.


Oh, cool?


> In 1940, after Whittle's jet had flown, the F.1 would be changed to the pure jet F.2. And would lead, eventually, to the Armstrong-Siddeley Sapphire. The Sapphire would be built under licence by Wright as the J-65.


That I know about...


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## wuzak (Sep 5, 2017)

Zipper730 said:


> Did it have a turbine for every stage?



No.


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## fubar57 (Sep 5, 2017)

wuzak said:


> No.



No?


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## Shortround6 (Sep 5, 2017)

Zipper730 said:


> Was he marketing them for power-generation or propulsion?



Neither, these were compressors, that is air pumps, First was a ventilation air pump for a warship. Others were for ventilating mines or supplying air for industrial purposes. 

For the same power input they could get more air, either pressure or volume from a different form of air pump.

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## wuzak (Sep 5, 2017)

fubar57 said:


> No?



I probably should say that I doubt it.

I should think there were 3 turbine stages - one left rotating, one right rotating and a power take-off turbine (it was a turboprop/turboshaft).

Though I am only guessing. I haven't quite worked out by what mechanism the counter-rotating stages are driven. It was said to be quite complex.


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## fubar57 (Sep 5, 2017)

Just funnin' with ya man. I have no idea what you guys are talking about but I enjoy learning

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