PROP SAMPLE CASE: BARNARD'S RV-6A - Max Cruise @ @ NOTE- The "@" sign allows comments to be inserted on the remainder of a line. @ The INPUT file is always required to run PROP and must begin with a @ single title line. All input is echoed to the OUTPUT file which @ subsequently may be used as an input file by renaming it to INPUT. @ CONTROL @ Input group name for control group type data @ @ Optimize for maximum velocity at a fixed RPM: NPAYOFF=2 @ 0=Calibration, 1=Point Design, 2=Max Velocity IOPT=1,2,3 @ 1=AF, 2=DIAM, 3=RPM - Enter one to three values @ to select which design variable(s) you want optimized END @ Terminates the above input group so another can be selected @ DESLIM @ Group name for design constraints AFLIM=70,120 @ Permitted Activity Factor Range DLIM=50 74 @ Permitted Diameter Range END DESVAR @ Input group name for design group type data @ DIAM=70 PITCH=74 @ initial propeller size RPMREF=2618 @ initial or reference rpm ALTCRS=7079 @ Cruise Altitude DREF=70 @ Reference Propeller diameter ADRAG= 2.27865610328028 @ Result of Flight Calibration (R.A.F.6) BACAL= 4.28878715137178 @ Result of Flight Calibration (R.A.F.6) @ EFFECTIVE ABDES= 2.42267567824696 @ Result of F. C.: Reference only @ EFFECTIVE PITCH= 89.3762038558346 @ " @ EFFECTIVE BLADE ANGLE= 28.4529089988911 @ " WTGRSS=1634 @ Aircraft gross flight weight SPAN=23 @ Wing Span: Used for induced drag VDES=199.7 @ Initial guess or reference velocity OSWALD=.851 KS=1.7 @ Estimated values- defaults may usually be used END @ Terminates the DESVAR input group (optional) TABLES @ Tables Group for reference propeller & engine data STA=.2,.3,.4,.5,.6,.7,.8,.9,1. CHORD=5.217 5.138 5.090 5.023 4.852 4.527 4.080 3.424 2.651 TCTAB=.4064 .2937 .2436 .2007 .1684 .1440 .1355 .1151 .0902 RPMTAB=2250 2700 @ more points are better HPTAB=164 180 @ does not account for ram boost, so some error SFCTAB=.67 .54 @ estimated sfc END @------------------------------------------------------------------- @ @ This file can serve as a template and any DOS text editor may be @ used to modify it. The "@" command makes extensive input file @ documentation possible. @ @ RUN - Runs this file directly bypassing the interactive menu EOF @ Optioal end-of-file command: Return to Interactive Main Menu COMPUTED AF= 85.30 THICKNESS RATIO AT 75% TIP STATION = 0.1394 PROP SAMPLE CASE: BARNARD'S RV-6A - Max Cruise @ 11/03/93 10:19:53.23 >>>> OPTIMIZED DESIGN: VARIABLE INITIALLY OPTIMIZED LOWER LIMIT UPPER LIMIT OPTION FLAG AFDES 85.2985 83.1075 70.0000 120.000 IOPT( 1)= 1 DIAM 70.0000 72.1851 50.0000 74.0000 IOPT( 2)= 2 RPM 2618.00 2700.00 2250.00 2700.00 IOPT( 3)= 3 PROPELLER DESIGN CRUISE PERFORMANCE NUMBER OF BLADES = 2 VELOCITY, MPH = 201.255 BLADE ACTIVITY FACTOR= 83.1075 ALTITUDE, FEET = 7079.00 DIAMETER, INCHES = 72.1851 DENSITY, SLUGS = 0.192319E-02 EFFECTIVE PITCH, IN = 84.6035 THRUST, POUNDS = 225.513 PITCH ANGLE DEG @75%R= 26.4470 DRAG, POUNDS = 225.513 BLADE ALPHA DEG @75%R= 1.61257 THRUST HP = 121.028 DESIGN LIFT COEF, CL = 0.2475 SHAFT HP = 139.577 THRUST COEF, CT = 0.0442 HP AVAILABLE = 139.577 POWER COEF, CP = 0.0556 PROPELLER RPM = 2700.00 SPEED_POWER COEF, CS = 1.9434 ENGINE RPM = 2700.00 ADVANCE RATIO, J = 1.09043 REDUCT FACTOR = 1.00000 EFFICIENCY, ETA = 0.867105 SFC, LB/HP/HR = 0.540000 ETA COMPRESS CORRECT.= 0.00% MILES/GALLON = 16.0210 ETA PROFILE DRAG CORR= -0.03% FUEL FLOW, PPH = 75.3718 ETA DIAMETER CORRECT.= 0.36% FUEL FLOW, GPH = 12.5620 ADRAG, SQ FT = 2.27866 SOUND SPEED,FPS= 1088.92 PITCH CALIBRTN, BACAL= 4.28879 TIP SPEED, FPS = 900.181 RATED PITCH, INCHES = 69.2646 TIP MACH NUMBER= 0.826677 CONSTRAINT VALUES MEASURE THE SUCCESS OF THE OPTIMIZATION. EQUALITY CONSTRAINTS ARE SATISFIED WHEN = 0 INEQUALITY CONSTRAINTS ARE SATISFIED WHEN >= 0 TYPE: EQUALITY = 0, UPPER BOUND = 1, LOWER BOUND = -1 SYSTEM CONSTRAINT VALUES: NAME TYPE ACTIVE INACTIVE ETAMAX 0 0.1233E-06 PAYOFF=-2.01455 (-VDES) NRUN= 43 NC= 1 NEC= 1 PROGRAM OUTPUT DEFINITIONS AFDES Activity factor per blade. The higher the activity factor, the more power a blade can absorb (or is required). For a given diameter, activity factor increases with blade width. ALPHA Blade angle-of-attack at the 75% radius, degrees. The angle the incoming air flow makes with the airfoil zero-lift-line. ANGLE Blade zero-lift-line pitch angle at 75% tip radius station (pitch) measured with respect to the plane of rotation, degrees. CL Blade lift coefficient. Design lift coefficient for cruise. CP Power coefficient: A non dimensional ratio relating power required to air density, propeller speed squared and propeller diameter raised to the fifth power. Power required is proportional to the fifth power of diameter for other factors being equal. PROGRAM OUTPUT DEFINITIONS CT Thrust coefficient: A non dimensional ratio relating thrust produced to air density, propeller speed squared and propeller diameter raised to the fourth power. Thrust produced is proportional to the fourth power of diameter for other factors being equal. CS SPEED_POWER coefficient, J/CP^(1/5). A design parameter used in determining maximum efficiency for cruise propellers. DIAM Propeller diameter, inches DRAG Aircraft drag, pounds ETA Propeller efficiency: ETA=CT*J/CP A measure of how much power is delivered to the air stream by the propeller relative to power delivered by the engine. This value includes compressibility, profile drag and relative diameter corrections. PROGRAM OUTPUT DEFINITIONS ETA COMPRESS CORRECT: A factor indicating the percentage propeller efficiency is reduced due to sonic compressibility effects at the blade tip. Zero indicates no compressibility losses. The optimizer tries to design on balance to minimum loss. ETA PROFILE DRAG CORR: An efficiency correction due to blade width or total activity factor and represents the induced losses. ETA DIAMETER CORRECT: Corrects for the relative influence of body and engine nacelle size to propeller diameter. Assuming that the reference point is accounted for in the effective pitch and ADRAG calibration, this correction is the increase or decrease in efficiency from the calibrated reference point. FFGPH Fuel flow in gallons per hour FFPPH Fuel flow in pounds per hour HP Maximum Horsepower Available (HPA) from the engine at a given RPM. PROGRAM OUTPUT DEFINITIONS J Advance ratio J=(V*88)/(RPM*DIAMETER) Where: V=mph, DIAMETER=ft. In flight the propeller advances a distance of J times the DIAMETER per revolution. MPG Aircraft miles per gallon of fuel NB Number of blades PITCH Pitch of chord line at the 75% radius station, inches. The geometric or theoretical advance of the propeller per revolution. RHO Atmospheric density, slugs SFC Specific fuel consumption, lb/hp/hr SHAFT HP: Required input horsepower to the propeller shaft (SHP) before efficiency losses. THRUST Propeller thrust, pounds PROGRAM OUTPUT DEFINITIONS THRUST HP: Net horsepower (THP) delivered to the atmosphere by the propeller after efficiency losses and required for flight, (THP=SHP*ETA). TPMACH Tip Mach number V Aircraft velocity, miles/hour VS Speed of sound, feet/second VT Tip speed, feet/second NRUN Number of trial designs run PAYOFF Objective or merit function. A quantitative measure of the design goal such as maximum velocity or climb rate. ELAPSED RUN TIME= 23.560 SEC PROP OPTIMIZER (tm) v1.90 Copyright 1993 Donald R Bates - All Rights Reserved BATES ENGINEERING, 2742 Swansboro Road, Placerville, CA 95667 Phone/FAX 916-622-1886 Copy Date 10/31/93