Usage Notes

Compatibility Info

Propgen has been tested and is known to work with Windows XP 32 bit, Windows 7 32 bit and 64 bit, and Ubuntu Linux 32 bit. All testing has been with Sun's Java runtime.

PropGen will not run on 64 bit Linux - this should be fixed in the next release.

Overview

PropGen is agnostic as to whether you're working with a power-turbine or propeller. If you specify positive KWatts, for example, you are supplying energy and operating in propeller mode, generating thrust. If you specify negative KWatts, you are extracting energy from the fluid and operating as a generator. If your KWatt request (or lbs thrust, or SHP, etc) exceeds device capacity then PropGen will eventually give up and output the closest value along with warning message stating "COULD NOT CONVERGE ON CP OR CT", and possibly other warnings such as "STALLED ROTOR".

PropGen has known wake stability issues when you get close to (positive or negative) section stall angles. If this happens a "POOR WAKE ANGLE CONVERGENCE: xx.xxxx degrees" warning is printed. If the xx.xxxx value is less than 10 degrees the solution could be close enough... that's for you to decide. Often, a small input change is all that's needed to get a converged wake; e.g. change 20 SHP to 20.1 SHP, etc.. Wake stability issues should be addressed within the next 2 releases.

 

Aircraft Propellers

All performance and inverse design features are enabled. There are no known limitations.

 

Wind Turbines

All performance features are enabled; however, the wake sometimes becomes unstable for deep stall scenarios, which are typical of stall regulated wind turbines. If you have a scenario that doesn't converge, try making a small input change (e.g. change BETA from 5 degrees to 4.9 degrees, or change power from -20 Kw to -20.1 Kw; etc)... often that's all it takes to get a converged solution. If you get a converged solution it's very likely a good one.

There should be no performance computation issues with variable pitch wind turbines.

Remember to specify negative power values when doing turbine computations... and positive ones for propellers.

The inverse design feature is not yet supported for wind turbines.

 

Marine Propellers

All performance and inverse design features are enabled. Aside from a lack of accounting for cavitation, there are no known limitations (inviscid considerations aside). You'll need to manually define fluid properties as described in Alternate Fluids and Atmospheres.

 

Marine Turbines

Capabilities and limitations are the same as Wind Turbines, discussed above. You'll need to manually define fluid properties as described in Alternate Fluids and Atmospheres. The most likely usage model for this is in the application of tidal power generation.

 

Development Schedule

PropGen is still in development and the planned feature set is below. Time available for this project is in constant flux - don't be disappointed if target dates slip.

Fill out this form to be notified of new releases.

Feature/Description Complex Priority Target
Polar Data: Contributions will be added to the dataset after review. See dataset requirements for details. low yes TBD
DXF: output DXF files for designs. Look here for instructions on how to generate these manually for now. medium yes TBD
Wind Turbines: inverse design improvements high yes Apr'10
DXF: output visualization of wake vortex sheet... because it looks cool. low-medium no TBD
Add a user tunable "stall delay model" for the polar data. low no TBD
Add a user tunable "wake dissipation model". low no TBD
       
       

 

Airfoil Database Description

The range of airfoils available to PropGen is limited to that supplied with the distribution. I intend to constantly expand the database as time permits. If you have a "full array" of polar data (CL, CD, alpha, and geometry) and are willing to share it with the world, then contact me and I will review then add the data (see dataset requirements for an idea of what's needed). That data will be available to all PropGen users.

If you want to use proprietary airfoils, then you need to request an unlocked version of PropGen.

 

Current Airfoil Datasets

Dataset (donated by) Description and Derivation
NACA_65 (self)

This data was extracted from Appendix B of "Summary of Propeller Design Procedures and Data" by Borst. The data is mostly based upon wind tunnel tests, but there's also a fair amount of heuristic and interpolated data. Dataset ranges:
* Camber: -0.7 --> +0.7
* Mach: 0.3-->1.6
* Reynolds: 1000000-->3000000
* T/C: 0.04-->0.3
* Alpha: -30 --> +30

S809_Re1M (self)

This set contains a single S809 airfoil at Re = 1M. The S809 was optimised for stall regulated wind-turbines. The data was extracted from a variety of sources described at CER_tapered_10m_analysis.htm. Dataset ranges:
* Camber: ~0
* Mach: ~0
* Reynolds: 1000000
* T/C: 0.21
* Alpha: -40-->40

 

Export Limitations

You may not use or otherwise export or reexport this PropGen Software except as authorized by United States law and the laws of the jurisdiction in which the PropGen Software was obtained. In particular, but without limitation, the PropGen Software may not be exported or re-exported (a) into any U.S. embargoed countries or (b) to anyone on the U.S. Treasury Department's list of Specially Designated Nationals or the U.S. Department of Commerce Denied Person’s List or Entity List. By using the PropGen Software, you represent and warrant that you are not located in any such country or on any such list. You also agree that you will not use these products for any purposes prohibited by United States law.

 

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