Laminarflow

Laminar Flow Rodney Bajnath, Beverly Beasley, Mike Cavanaugh AOE 4124 March 29, 2004

Introduction ,[object Object],[object Object]

Natural Laminar Flow ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],NACA Report No. 824

Natural Laminar Flow ,[object Object],[object Object],[object Object],[object Object],NACA Report No. 903

Natural Laminar Flow ,[object Object],[object Object],XFOIL

Natural Laminar Flow ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],1. NASA Contractor Report No. 201686, 1997. 2. Lutz, “Airfoil Design and Optimization,” 2000. 3. Garrison, “Shape of Wings to Come,” Flying 1984. 4. NASA Technical Memorandum 85788, 1984.

Natural Laminar Flow: Case Study ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Fujino et al, “Natural-Laminar-Flow Airfoil Development for the Honda Jet.”

Natural Laminar Flow: Case Study (Continued) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Fujino et al, “Natural-Laminar-Flow Airfoil Development for the Honda Jet.”

Natural Laminar Flow: Case Study (Continued) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Fujino et al, “Natural-Laminar-Flow Airfoil Development for the Honda Jet.”

Natural Laminar Flow: Case Study (Continued) ,[object Object],[object Object],[object Object],[object Object],[object Object],Fujino et al, “Natural-Laminar-Flow Airfoil Development for the Honda Jet.”

Laminar Flow Control ,[object Object],[object Object],[object Object],[object Object],Ref: McCormick, “ Aerodynamics, Aeronautics and Flight Mechanics ,” pg. 202. plenum chamber outer skin inner skin Boundary layer thins and becomes fuller across slot

Notable Laminar Flow Control Flight Test Programs Ref: Applied Aerodynamic Drag Reduction Short Course Notes, Williamsburg,VA 1990. effects of sweep on LF encountered full chord LF R C = 47x10 6 new LF wings for program suction through nearly full span slots – both wings X-21 (Northrup/USAF) jet bomber 30 ° sweep 1963-1965 no special maintenance required lost LF in clouds & during icing LE protection effective LF maintained to front spar through two years of simulated airline service two leading edge gloves Lockheed – slot suction & liquid leading edge protection McDD – perforated skin & and bug deflector JetStar (NASA) 4-engine business jet 1985-1986 at M local >1.09 shocks caused loss of LF Full chord LF 0.6 < M < 0.7 R C = 36x10 6 NACA 63-213 upper surface wing glove suction – 12, 69, 81 slots F-94 (Northrup/USAF) jet fighter 1954- 1957 Monel/Nylon cloth 0.007” perforations full chord LF M~0.7 / R C =30x10 6 upper surface wing glove suction - porous surface full chord suction Vampire (RAE) single engine jet 1955 Engine/prop noise effected LF surface quality issues LF to 45% chord (LF to min C p ) R C = 30x10 6 NACA 35-215 10’x17’ wing glove section suction slots first 45% chord Douglas B-18 (NACA) 2-engine prop bomber 1940 Comments LF Result Test Configuration Aircraft Date

Why Does LFC Reduces Drag? ,[object Object],XFOIL output

Why Does LFC Reduce Drag? ,[object Object],XFOIL Output upper surface lower surface

Why Does LFC Increases C L MAX ? ,[object Object],Ref: A.M.O. Smith, “High Lift Aerodynamics,” Journal of Aircraft, Vol. 12, No. 6, June 1975

Raspet Flight Research Laboratory Powered Lift Aircraft ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Photographs Courtesy of the Raspet Flight Research Laboratory

Suction Power Required for 23012 Cruise Condition ,[object Object],Joseph Schetz, “Boundary Layer Analysis,” Equation (2-37) 0.035” 0.0025” dia 45” chord 12” span ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Laminar Flow Control Approaches 1). Leading Edge Protection 2). Distributed Suction (perforated skin or slots) 3). Hybrid Laminar Flow Control Ref: Applied Aerodynamic Drag Reduction Short Course Notes, …….Williamsburg,VA 1990.

Laminar Flow Control Problems/Obstacles ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Ref: Applied Aerodynamic Drag Reduction Short Course Notes, Williamsburg,VA 1990. Ref: Mark Drela, “XFOIL 6.9 User Guide”, MIT Aero & Astro, 2001

Boundary Layer Transition Flight Tests on GlasAir ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

CENTURIA ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Centuria Design Details ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Drawing by Anne Ocheltree & Nick Smalley

Calculating Laminar Flow 60% 100% Laminar Turbulent Laminar Turbulent Wing & Tail Fuselage 40% 100%

Fuselage Laminar to max thickness Wing 60% LM flow upper and lower surface V-Tail 60% LM flow upper and lower surface

Centuria NLF Manufacturing Tolerances R h,crit h crit (in.) 900 0.0072 inches 1800 0.0143 inches 2700 0.0215 inches 15,000 0.1195 inches Carmichael’s waviness 0.0139 inch/inch criteria Ref: A.L. Braslow, “Applied Aspects of Laminar-Flow Technology,” AIAA 1990  h

Conclusions ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

References ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Laminarflow

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