PROPID Manual Updates (Beta Version 3.0)

UIUC Applied Aerodynamics Group
Department of Aerospace Engineering
University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
Michael S. Selig
with contributions by Nikhil Raj

Last update 10/11/98

This is a definition of some of the keywords that have not been defined in the PROPID Manual. Most of the keywords that are required in the input file are defined and explained in the manual. The examples included in this list are those which are optional in the input file or those which are alternatives to the definitions already included in the PROPID Manual.

AIRFOIL_FAMILY  <KNODE<IAFMLY>>
       <AFX<IAFMLY,1>>             <IDXAF<IAFMLY,JNODE>>         <BLENDDST<IAFMLY,JNODE>>
       ...
       <AFX<IAFMLY,JNODE>>         <IDXAF<IAFMLY,JNODE>>         <BLENDDST<IAFMLY,JNODE>>
       ...
       <AFX<IAFMLY,KNODE<IAFMLY>>> <IDXAF<IAFMLY,KNODE<IAFMLY>>> <BLENDDST<IAFMLY,KNODE<JNODE>>>

AFX<..> - location of airfoil IDXAF, where IDXAF is the index of the airfoil listed in the AIRFOIL_MODE line.
KNODE<..> - number of nodes.
BLENDDST<..> - the distribution function used to determine the blending. Note: the first BLENDDST value must be 1. How to use: Set the blend dst on the AIRFOIL_FAMILY line. Plot out the thickness distribution and blend distribution <AFBLDDST<.>> to see if it looks smooth. In general, a smooth t/c distribution will be obtained if the blend function is weighted according to the airfoil thickness distribution.

Example 1
r/R     tc    blend
0.0   0.24    1.00
0.5   0.21    0.25
1.0   0.20    0.00

Example 2
r/R     tc    blend
0.0    .24    1.0
0.3    .24    0.9
0.7    .21    0.5
1.0    .24    0.9

Basically, you need to play around with the blend function, while monitoring it as well as the thickness distribution and weight distribution (which gets determined).

AirfoilFileNames
<IAFFILES>
!IAFFILES - the number of stations at which data is required. Same as the StationRe line.
affile<1>
title2<1>
...
affile<jaffiles>
title2<jaffiles>
...
affile<iaffiles>
title2<iaffiles>

AIRFOIL_MODE <IAFCASE> 
                    !  1 --- enter airfoil data in PROPPC order (unformatted)
                    !  2 --- airfoil model
                    !  3 --- read in raw airfoil data files
                    !  4 --- read in raw airfoil data files

If iafcase = 2 then enter the following data

   <TC<1>>  <ALFA1<1>>  <CL1<1>>  <ALFA2<1>>  <CL2<1>>  <ALFA3<1>>> -
      <LBUCKET<1>>  <ALFA0<1>>
     ...
   <TC<NS>> <ALFA1<NS>> <CL1<NS>> <ALFA2<NS>> <CL2<NS>> <ALFA3<NS>>>
      <LBUCKET<NS>>  <ALFA0<NS>>

Note the either ALFA1 or CL1 for a given data point should be zero to indicate that the other point will be determined by the relation C_l = 2 × Pi × alfa.
If iafcase = 3, then airfoil data is in order of C_l, C_d, alfa.

  <IAF>
  <AFFILE<1>>
  <AFTHK<1>>   <AFSTALL<1>>   <STDELAY<1>>  |<CLMAXN<1>> <ALINSERT<1>> <DUSTART<1>> <DUEND<1>>
   ...
  <AFFILE<JAF>>
  <AFTHK<JAF>> <AFSTALL<JAF>> <STDELAY<JAF>>|<CLMAXN<JAF>> <ALINSERT<JAF>> <DUSTART<JAF>> <DUEND<JAF>>
  ...
  <AFFILE<IAF>>
  <AFTHK<IAF>> <AFSTALL<IAF>> <STDELAY<IAF>>|<CLMAXN<IAF>> <ALINSERT<IAF>> <DUSTART<IAF>> <DUEND<IAF>>

AFFILE<.> - airfoil file name: pd.*
AFTHK<.> - airfoil thickness
AFSTALL<.> - airfoil stall angle of attack
STDELAY<.> - stall delay of the airfoil (i.e., where you want the flat plate model to kick in)
CLMAXN<.> - the C_lmax of the pd* file. Get this by looking at the pd* files.
ALINSERT<.> - the angle of attack at which to shift the C_l-alpha data to higher values in the corrigan model
DUSTART<.> - the angle of attack at which the application UIUC model is started
DUEND<.> - the angle of attack at which the application UIUC model is ended.

Note: The C_l and C_d data must extend to a very high angle of attack. See pd.* files for example.

For iafcase = 4, airfoil data is in order of alfa, cl, cd

AlfaMinMaxInc <IANGMODE>
! 1 --- min, max and increment follow
For IANGMODE = 1, then enter the following data
<ALFAMIN> <ALFAMAX> <ALFAINC>
! 2 --- individual angles are given

CHORD_BASE     0.0911
     2
     .5    .000
     1.    .000
TWIST_RELATIVE     2
     .5    .000
     1.    .0

This is an optional way to enter the chord and twist distributions. Enter the base chord, then relative chord and twist distributions. At least two points are required for the relative distributions, as shown above.


CORRIGAN_EXPN <EXPN>

This is used to turn on the Corrigan stall model and EXPN is the exponent used by the model. This line must come before the airfoil data files are specified because this sets a flag for the original airfoil data to be written to a buffer file as soon as it is read in.

StationRe <IMODECF>
! 1 --- blade stations and Re follow
! 2 --- use all blade stations and Re's corresponding to previous analysis

For IMODECF = 1 then enter the following data

      <IJSEGCF>
      <KJSEGCF<1>>       <RECF<1>>
      <KJSEGCF<.>>       <RECF<.>>
      <KJSEGCF<IJSEGCF>> <RECF<IJSEGCF>>

If RECF<.> is zero, then the Re from the previous analysis is used

TIPON
! forces the tip loss model to be on always
! (even when past the stall angle when otherwise it would be turned off)
! It is suggested that this always be on.

USE_AIRFOIL_FAMILY <KAFMLY>
KAFMLY - the index of the airfoil family to use.
If more than one family of airfoils is described along the blade span, then this line indicates to the code as to which family to use for the analysis mode.