Vance,
You are both a rocket scientist and a QB whiz. Please take a look at
this and see if you can find the incremental drag bug.
Also any suggestions for improvements as well.
I am now thinking of adding transonic lift and drag features
from Abbot & Von Doenhoff.

Anybody else that feels like helping out is also welcome.
Don't attack QB or you will get what-for :-)

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org

RPM = 2700
rps = RPM / 60
RadiusIncr = .25
maxwidth = .6
taperrat = .13
DragCoef = .07
LiftCoef = .4
CLS

OPEN "propang.dat" FOR OUTPUT AS #1
PRINT #1, "Six foot diameter prop and 2700 RPM"
PRINT #1, "Taper ratio = "; taperrat
PRINT #1, "Section drag coefficent = "; DragCoef
PRINT #1, "Section lift coefficent = "; LiftCoef
PRINT #1, "Maximum blade width in feet = "; maxwidth
PRINT #1,

PRINT #1, " A = Blade Radius in feet."
PRINT #1, " B = Blade Cord in feet."
PRINT #1, " C = Blade incremental area in square feet."
PRINT #1, " D = Cord Velocity in MPH."
PRINT #1, " E = Drag increment in pounds."
PRINT #1, " F = HP consumption increment."
PRINT #1, " G = Thrust increment in pounds."
PRINT #1, " H = Zero angle of attack angle in degrees."
PRINT #1,

FOR fps = 60 TO 360 STEP 20
MPH = fps * (60 / 88)

PRINT #1, "MPH = ";
PRINT #1, USING "###.#"; MPH
'PRINT #1, "       Speed in FPS";
'PRINT #1, USING "##########"; fps

PRINT #1, "A     B      C      D     E      F      G      H"

FirstAngFlg = 1
TotDrag = 0
TotThrust = 0
TotHP = 0
FOR radius = .25 TO 3 STEP RadiusIncr


PRINT #1, USING "#.#"; radius;

BladeCord = (maxwidth - taperrat * radius)
PRINT #1, USING "###.###"; BladeCord;

BladeArea = BladeCord * RadiusIncr
PRINT #1, USING "###.###"; BladeArea;

circfps = (3.1416 * 2 * radius * rps)
circMPH = (3.1416 * 2 * radius * rps) * (60 / 88)
'PRINT #1, USING "#####.#"; circMPH;

CordMPH = (circMPH ^ 2 + MPH ^ 2) ^ .5
PRINT #1, USING "#####"; CordMPH;

DragIncr = BladeArea * DragCoef * .0026 * CordMPH ^ 2
PRINT #1, USING "###.###"; DragIncr;
TotDrag = TotDrag + DragIncr

HPIncr = (DragIncr * CordMPH * (88 / 60)) / 550
PRINT #1, USING "###.###"; HPIncr;
TotHP = TotHP + HPIncr

ThrustIncr = BladeArea * LiftCoef * .0026 * CordMPH ^ 2
PRINT #1, USING "####.##"; ThrustIncr;
TotThrust = TotThrust + ThrustIncr


AAngle = 90 - ((ATN(circfps / fps)) * 57.295)
IF FirstAngFlg = 1 THEN FirstAng = AAngle
FirstAngFlg = 0
PRINT #1, USING "#####.##"; AAngle



NEXT
Twist = FirstAng - AAngle
PRINT #1,
PRINT #1, "Twist = ";
PRINT #1, USING "##.##"; Twist;
rootrat = Twist / FirstAng
PRINT #1, "    Ratio Twist/Root = ";
PRINT #1, USING "#.##"; rootrat;
tiprat = Twist / AAngle
PRINT #1, "    Ratio Twist/Tip = ";
PRINT #1, USING "#.##"; tiprat

Thrust2 = TotThrust * 2
PRINT #1, "Thrust =";
PRINT #1, USING "####"; Thrust2;

ThrustHP = (Thrust2 * fps) / 550
PRINT #1, "     Thrust  HP =";
PRINT #1, USING "#####"; ThrustHP;

EngineHP = ThrustHP * 1.2
PRINT #1, "    Engine HP =";
PRINT #1, USING "#####"; EngineHP


TotHP2 = TotHP * 2
'PRINT #1, "          Total HP consumed =";
'PRINT #1, USING "###.##"; TotHP2

TotDrag = 0
TotThrust = 0
TotHP = 0

PRINT #1, "----------------------------------------------------------------"

'PRINT #1,
NEXT
CLOSE

SHELL "more < propang.dat "
SYSTEM