BASIC AERODYNAMICS PART I Federal Aviation Administration PRESENTED
BASIC AERODYNAMICS PART I Federal Aviation Administration PRESENTED BY: Dennis H. Whitley FAASTeam Lead Representative NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 1
MY MOTTO SHOW ME A PILOT THAT CAN’T ANSWER A CORRELATIVE QUESTION AND/OR CAN’T PERFORM A GIVEN TASK, & I’LL SHOW YOU A PILOT THAT DOESN’T UNDERSTAND WHAT HE/SHE IS TRYING TO ACCOMPLISH. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 2
FLIGHT INSTRUCTING MUST NOT BE THE BY-PRODUCT OF BUILDING FLIGHT HOURS. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 3
BUILDING FLIGHT HOURS MUST BE THE BY-PRODUCT OF FLIGHT INSTRUCTING. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 4
SAFETY COMMITMENT VS DEDICATION NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 5
THIS DISCUSSION IS BASED ON SUBSONIC AIRCRAFT AND WILL BE “VERY BASIC” “NO FORMULAS” “VERY LITTLE MATH” NORTH FLORIDA FSDO-15 JANUARY 27, 2010 AERODYNAMICS PART I Federal Aviation Administration 6
WE WILL TALK ABOUT ATMOSPHERIC PRESSURE 4 FORCES LIFT/WEIGHT/THRUST/DRAG GROUND EFFECT TURNING TENDENCIES TRIM DEVICES AERODYNAMICS OF SPINS SLIPS/SKIDS ADVERSE YAW NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 7
WHAT IS ATMOSPHERIC PRESSURE? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 8
ATMOSPHERIC PRESSURE IS THE WEIGHT OF ALL THE AIR UPON THE SURFACE OF THE EARTH.
WHAT DOES 30 hg MEANS? HOW WAS ATMOSPHERIC PRESSURE MEASURED? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 10
36 YARD STICK 36 INCHES TALL
YARD STICK 36
YARD STICK 36
HOW WAS THE DROP OF PRESSURE WITH ALTITUDE VERIFIED?
HOW WAS THE WEIGHT OF THE AIR DETERMINED? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 17
WHAT IS AN ALTIMETER? A PRESSURE DIFFERENTIAL GAUGE NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 20
FROM SOURCE 15 20 25 15 30 10 0 HG 0 15 20 25 30 10 35 5 40 0 HG 25 35 5 40 FROM SOURCE 30 10 35 5 20 HG 40
Static Port Kollsman Window
static port pressure 31. 00 hg. 31. 00 SEA LEVEL sea level pressure 31. 00 hg.
static port pressure 23. 00 hg. 31. 00 sea level pressure 31. 00 hg.
WHAT IS ALTIMETER SETTING? SEA LEVEL PRESSURE CORRECTED FOR NONSTANDARD TEMPERATURE.
WHAT IS THE MAIN REASON THAT AN AIRPLANE IS ABLE TO FLY? BECAUSE OF THE WEIGHT OF THE AIR. In other words the aerodynamic effect air has on the aircraft. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 26
DEFINITION OF AERODYNAMICS The branch of science that deals with the forces produced by air flowing over specially shaped surfaces called airfoils. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 27
IS THERE ANY THING WRONG WITH THIS PICTURE? TWO THINGS THE FLOWING OF THE RELATIVE WIND THE DIRECTION OF THE RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 28
CAN WE FLY WITH A FLAT WING?
1 ST LAW: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. 3 RD LAW: For every action there is an equal and opposite reaction. AT CRUISE COSTANT ALTITUDE NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 30
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 31
MINIMUM MANEUVERING SPEED SLOW FLIGHT NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 32
STALL PA-28 SERIES NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 33
WHAT IS THE DEFINITION OF FOIL? TO PREVENT FROM BEING SUCCESSFUL TO THWART NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 34
AIRFOIL • Any surface designed to deflect the airflow passing over it or striking it, and thereby obtaining an useful reaction AN AIRFOIL IS AN AIR DEFLECTOR
HOW MANY AIRFOILS ARE THERE? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 36
• AIRPLANE WING. • AILERONS. • SLATS • LANDING FLAPS. • VERTICAL STABILIZER. • RUDDER. • HORIZONTAL STABILIZER. • ELEVATOR/STABILATOR • TRIM TABS. • PROPELLER. • ROTOR BLADE. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS • FUSELAGE. • FEARING. • STRUTS. Federal Aviation Administration 37
WHAT IS LIFT? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 38
A FORCE CREATED BY A DEFLECTION OF AIR AND PRESSURE DIFFERENTIAL AROUND AN AIRFOIL. IS CALLED LIFT WHEN IT ACTS UPWARD. WHEN IT ACTS DOWNWARD IS CALLED NEGATIVE LIFT. WHEN IT ACTS SIDEWAYS IS CALLED SIDE LIFT. WHEN IT ACTS FORWARD IS CALLED THRUST NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 39
HOW IS LIFT CREATED? AIR PASSING BY AN AIRFOIL DEFLECTION -- ISSAC NEWTON AIR’S CHANGE OF DIRECTION--BERNOULLI'S PRINCIPLE PRESSURE DIFERENTIAL-- BERNOULLI'S PRINCIPLE NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 40
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 41
WHAT’S WRONG WITH THIS PICTURE NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 42
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 43
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 44
CAN WE FLY WITHOUT THE HELP OF BERNOULLIS? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 45
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 46
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 47
THRUST • Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a proportional but opposite force on that system. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 48
LIFT • LIFT is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a proportional but opposite force on that system. • Thrust is LIFT DIRECTED FORWARD. NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 49
THE PROPELLER’S NORTH FLORIDA REGION OCTOBER 02, 2010 DEFLECTION OF AIR BASIC AERODYNAMICS Federal Aviation Administration 50
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 51
NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 52
DRAG NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 53
PARASITE DRAG FORM INTERFERENCE NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 54
INDUCED DRAG GROUND EFFECT COMMANDER TYSON NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 55
ASSUMED ANGLE OF ATTACK ASSUMED LIFT STAGNATION AREA UPWASH RELATIVE WIND DOWNWASH ASSUMED RELATIVE WIND IS THAT RIGHT? NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 56
STAGNATION AREA RELATIVE CURRENT NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS UPWASH DOWNWASH Federal Aviation Administration 57
INDUCED ANGLE OF ATTACK ASSUMED LIFT INDUCED RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 58
DOWNWASH INDUCED ANGLE OF ATTACK ASSUMED LIFT INDUCED RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 59
DOWNWASH ASSUMED LIFT INDUCED ANGLE OF ATTACK INDUCED LIFT WING TIP VORTICES TOTAL ENDUCED DRAG INDUCED RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 60
WING THREE-DIMENSIONAL FLOW UPWASH MODIFIES RELATIVE WIND DOWNWASH PULLS BACK ON LIFT VECTOR WING TIP VORTICES PULLS LIFT VECTOR FURTHER BACK
DOWNWASH ASSUMED LIFT INDUCED ANGLE OF ATTACK INDUCED LIFT WING TIP VORTICES TOTAL ENDUCED DRAG INDUCED RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 62
ASSUMED LIFT INDUCED ANGLE OF ATTACK DOWNWASH INDUCED LIFT INDUCED RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 63
ASSUMED LIFT INDUCED ANGLE OF ATTACK INDUCED LIFT INDUCED RELATIVE WIND NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 64
WASHOUT NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 65
WHAT DOES THE STABILATOR DO?
WHAT DOES THE ANTI-SERVO TAB DO?
STABILIZED UNACCELERATED CLIMB A B C
IF DESCENDING IN A 60 ° BANK HOW MANY G ’S?
DYHEADRAL NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 70
ADVERSE YAW NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 73
OVERBANKING TENDENCIES NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 74
MANEUVERING SPEED VA NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 75
LOAD FACTOR NORTH FLORIDA REGION OCTOBER 02, 2010 BASIC AERODYNAMICS Federal Aviation Administration 76
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