Page 4 - Principles of flight – Helicopter

5. Flyveprincipper

Helikopter

Indholdsfortegnelse:

5.1 Indledning ................................................................. 6

5.1.1 Standardforhold ................................................................. 6

5.1.2 Newtons Love .................................................................... 7

5.1.3 Bernoullis teori ................................................................... 9

5.2 Indfaldsvinkel, opdrift, modstand ............................... 10

5.2.1 Indfaldsvinkel ..................................................................... 10

5.2.2 Modstand ........................................................................... 12

5.2.3 Opdrift / modstand ( Lift/ Drag ) ........................................ 15

5.2.4 Opdriftskoefficient og modstandskoefficient ...................... 16

5.3 Definitioner - rotorblade ............................................ 17

5.4 Rotorens airflow ........................................................ 24

5.4.1 Rotational airflow (Vr) ....................................................... 24

5.4.2 Bladvinkel og indfaldsvinkel .............................................. 24

5.4.3 Induceret strømning (flow) ................................................ 25

5.4.4 Rotor Thrust ...................................................................... 27

5.4.5 Kraften der modsvarer helikopterens vægt ....................... 28

5.4.6 Luftens tæthed .................................................................. 29

5.4.7 Bladvinkel og rotorens omdrejningstal og areal ................. 30

5.5 Rotor drag (torque) ................................................... 32

5.5.1 Effekt i torgue ved ændringer ............................................ 32

5.5.2 Halerotoren (anti torque rotor) ......................................... 36

5.5.3 Halerotorfejl ...................................................................... 37

5.5.4 Effekt af vind ..................................................................... 37

5.5.5 Mistet halerotorvirkning ................................................... 38

5.5.6 Tendency (Tail Rotor Drift) ................................................ 38

5.5.7 Tail Rotor Flapping ............................................................. 39

Henning Andersen, Midtjysk Flyveskole 2021, h.b.sunds@gmail.com S. 4