EXCELLENT OPPORTUNITIES EXIST FOR REDUCING THE DRAG OF AIRCRAFT BY INCREASING THE EXTENT OF LAMINAR BOUNDARY-LAYER FLOW OVER THE CONFIGURATION.

Period of Performance: 01/01/1984 - 12/31/1984

$48.9K

Phase 1 SBIR

Recipient Firm

Vigyan, Inc.
30 Research Drive
Hampton, VA 23666
Principal Investigator

Abstract

EXCELLENT OPPORTUNITIES EXIST FOR REDUCING THE DRAG OF AIRCRAFT BY INCREASING THE EXTENT OF LAMINAR BOUNDARY-LAYER FLOW OVER THE CONFIGURATION. RECENT TECHNOLOGICAL ADVANCES IN AIRPLANE CONSTRUCTION TECHNIQUES AND MATERIALS EMPLOYING BONDED AND MILLED ALUMINUM SKINS AND COMPOSITE MATERIALS ALLOW FOR THE PRODUCTION OF AERODYNAMIC SURFACES WITHOUT SIGNIFICANT ROUGHNESS AND WAVINESS, PERMITTING LONG RUNS OF NATURAL LAMINAR FLOW (NLF). ALSO, IMPROVED AERODYNAMIC DESIGN AND ANALYSIS METHODS FACILITATE THE SHAPING OF AIRPLANE SURFACES TO OBTAIN FLOW CONDITIONS FAVORABLE TO NLF. A MAJOR PORTION OF THE RESEARCH EFFORT FOR OBTAINING AND MAINTAINING LAMINAR FLOW ON AIRPLANE SURFACES HAS FOCUSED ON THE DELAY OF LAMINAR-TO-TURBULENT BOUNDARY-LAYER TRANSITION ON AIRPLANE LIFTING SURFACES. BODY SHAPING TO INCREASE THE EXTENT OF LAMINAR FLOW ON AIRPLANE FUSELAGES HAS RECEIVED MUCH LESS ATTENTION IN THE LITERATURE. A SIGNIFICANT REDUCTION IN AIRPLANE DRAG CAN BE OBTAINED, HOWEVER, WHEN NLF IS ACHIEVED ON THE FUSELAGE OF AN AIRPLANE. THE PHASE I OBJECTIVES ARE TO EVALUATE THE VARIOUS COMPUTATIONAL DESIGN AND ANALYSIS METHODS WHICH CAN BE APPLIED FOR THE DEVELOPMENT OF LOW-DRAG AERODYNAMIC FUSELAGE SHAPES AND TO ADDRESS THE ANALYTICAL DESIGN OF BODY SHAPES OF SEVERAL FUSELAGES AT FREE-STREAM UNIT REYNOLDS NUMBERS OF 1.5-3.0 MILLION PER FOOT. THE MOST PROMISING CONFIGURATION(S) WILL BE WIND-TUNNEL AND/OR FLIGHT TESTED DURING PHASE II.