Aerodynamic Characteristics of a NACA 4412 Airfoil

1 Aerodynamic Characteristics Aerodynamic Characteristics of a NACA 4412 Airfoilof a NACA 4412 AirfoilPresented By: David HeffleyPresented By: David HeffleyMentor: Dr. Van TreurenMentor: Dr. Van TreurenScholarScholar s Days DayJanuary 26, 2007 January 26, 2007 OverviewOverview ObjectiveObjective TheoryTheory ApparatusApparatus Experimental ComparisonExperimental Comparison ResultsResults SummarySummary RecommendationsRecommendationsObjectiveO bjective Study the lift and drag forces on a NACA 4412 Study the lift and drag forces on a NACA 4412 airfoilairfoil Resolve discrepancy in wind tunnel dataResolve discrepancy in wind tunnel data Develop experimental techniques for an airfoilDevelop experimental techniques for an Airfoil Compare wind tunnel dataCompare wind tunnel data Force Balance to Pressure DistributionForce Balance to Pressure Distribution

2 Baylor data to published NACA dataBaylor data to published NACA dataNACA 4412 AirfoilNACA 4412 Airfoil 4 digit code used to describe Airfoil shapes4 digit code used to describe Airfoil shapes 1st digit 1st digit --maximum camber in percent chordmaximum camber in percent chord 2nd digit 2nd digit --location of maximum camber along chord line (from leading edge)location of maximum camber along chord line (from leading edge)in tenths of in tenths of chordchord 3rd and 4th digits 3rd and 4th digits --maximum thickness in percent chordmaximum thickness in percent chord NACA 4412 with a chord of 6 NACA 4412 with a chord of 6 Max camber: camber: (4% x 6(4% x 6 )) Location of max camber: of max camber: aft of leading edge ( x 6aft of leading edge ( x 6 )) Max thickness: thickness.

3 (12% x 6(12% x 6 ))Mean camber lineChord lineChordx=0x=cMax thicknessMax camberLeading edgeTrailing edgexzTheoryTheoryLift, Drag and Angle of AttackLift, Drag and Angle of AttackStall AngleStall AngleViscousMomentumVc=== ReNumber Reynolds LiftDrag VRelativeWindTheoryTheorySVLCl221 =SVDCd221 =DynStatLocalPPPPC = =10)()(cxdCCCPUPLY =cycyPAPFXcydCCC)()(Relates lift and drag forces to the velocityDirect Method (Force Balance)Pressure Distribution (Pressure Ported Airfoil )Relates local pressure on an Airfoil to the velocity sincosXYlCCC = cossinXYdCCC+=Experimental ApparatusExperimental ApparatusBaylor University Wind TunnelBaylor University Wind Tunnel24 by 24 Test SectionTest Range.

4 0 150 ft/sOpen loop tunnelExperimental ApparatusExperimental ApparatusForce BalanceForce BalancePressure Tapped AirfoilPressure Tapped Airfoil18 pressure ports-18 to 20 DegreesBoth NACA 4412 airfoils are 24 wide with a 6 chord length-8 to 20 DegreesExperimental ComparisonExperimental Comparison Re = 3,000,000Re = 3,000,000 54 pressure ports54 pressure ports Variable density wind Variable density wind tunneltunnel 2424 chord lengthchord length Re = 150,000Re = 150,000 18 pressure ports18 pressure ports Constant density Constant density wind tunnelwind tunnel 66 chord lengthchord lengthNACAB aylor UniversityResultsResults Stall angleStall angle 11 degrees for 150,000 Re (Baylor)11 degrees for 150,000 Re (Baylor) 15 degrees for 3,000,000 Re (NACA)15 degrees for 3,000,000 Re (NACA)

5 Lift coefficient agrees within 2% of NACA Lift coefficient agrees within 2% of NACA published datapublished data Noticeable inaccuracies in drag coefficient data Noticeable inaccuracies in drag coefficient data from the pressure ported airfoilfrom the pressure ported Airfoil Drag coefficient is Re dependentDrag coefficient is Re dependentAerodynamic CurvesAerodynamic CurvesLift CurveLift CurveDrag CurveDrag Curve ClCdClHigher Re CurveLift CurveLift CurveClv of Attack (Degrees)Coefficient of LiftNACA Report563 NACA Report824 Force BalancePressureLift Pressure DistributionLift Pressure Distribution10 degrees CP vs.

6 Lower SurfaceExp Upper SurfaceNACA 563 Lower SurfaceNACA 563 Upper SurfaceDrag CurveDrag CurveCD v of LiftCoefficient of DragNACA 563 NACA 824 Force BalancePressureDrag Pressure DistributionDrag Pressure Distribution10 degrees CP vs. Lower SurfaceExp Upper SurfaceNACA 563 Lower SurfaceNACA 563 Upper SurfaceCCDDvs. Reynolds Numbervs. Reynolds NumberMunson, B. R., Young, D. F., and Okiishi, T. H., 2006, Fundamentals of Fluid MechanicsSummarySummary ObjectivesObjectives Study airflow over an Airfoil Study airflow over an Airfoil Resolve discrepancy in previous wind tunnel dataResolve discrepancy in previous wind tunnel data Compare wind tunnel dataCompare wind tunnel data ResultsResults Stall angle is a function of the Reynolds numberStall angle is a function of the Reynolds number Lift coefficient relates closely to published dataLift coefficient relates closely to published data Insufficient pressure ports to accurately map the pressure Insufficient pressure ports to accurately map the pressure

7 Distribution for drag coefficientdistribution for drag coefficient Drag coefficient highly dependent on Reynolds numberDrag coefficient highly dependent on Reynolds numberRecommendationsRecommendations Further experimentsFurther experiments NACA 0012 (Double the pressure ports)NACA 0012 (Double the pressure ports) Utilize BaylorUtilize Baylor s 3D printers 3D printer Develop lift and drag curves for future Develop lift and drag curves for future experiments to referenceexperiments to referenceQuestionsQuestions