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AERODYNAMICS FORCES
Introduction to Aerodynamic Forces
Actually Lift Force is not the only force working on the aircraft, during aircraft moving through the air. There are several aerodynamics forces working together at the same time. The forces are Thrust, Lift, Drag and Weight.
Forces and Directions
| No | Forces | Description | Direction | Source |
| 1. | Thrust |
Generated by aircraft engine and propeller or turbon fan or turbine to push air moved through the aircraft wing. As result, aircraft moved to direction contrary to air flow direction | Inline with aircraft direction | Engine |
| 2. | Lift Force | Created by air flow moving through aircraft wing which has specific airfoil. Higher lift force created if faster air flow or air flow moving into wider aircraft wing. | Perpendicular to air flow direction | Air flow through aircraft wing |
| 3. | Drag / Air Resistance | Created by aircraft body moved through air flow. Drag will be higher if air flow faster or aircraft has wider or more body parts which are not streamlines | Inline with air flow direction Aircraft body moved through air flow | |
| 4. | Weight | Aircraft weight or force to move aircraft down to the earth | Down | Aircraft+load Weight |
As all of forces working at the same time on aircraft, it will create a resultant of the forces, and aircraft should be moved to this direction, hence the magnitude of each forces or the balance and resultant of all forces should be taken into calculation very carefully when controlling aircraft.
The first thing to control aircraft is ensuring the balance of the forces and the direction of force resultant. The correct relationship is figured on the Figure above, where the lift and weight are higher then thrust and drag. The above relationship usually taken into aircraft design and calculated very carefully to create a aircraft general specifications.
1.2 Active and Created Forces
As described on the above tabel, only Thrust force which is created by the engine. This force we called Active Force or controlled force. It means we can control this force all the time by increasing aircraft engine or propeller rotation to get higher thrust force.
Other forces except weight are called created force. It means force created as impact from other forces i.e. Thrust. As impact of Thrust i.e. movement aircraft to forward will create Lift Force and also Drag Force. Controlling engine thrust should make the aircraft fly or land.
to be continued...
