PROP_DESIGN contains many examples, to help get users started. The included examples relate to the following products:

  • Airbus A400M Military Transport
  • Delta TFB1212GHE Computer Case Fan
  • General Atomics Predator B UAV
  • Mooney Acclaim Type S Single-Engine Piston Aircraft
  • Piaggio Aero P180 Avanti II Twin-Engine Turboprop Aircraft

These products were chosen as PROP_DESIGN examples, because they cover the typical operating range of aircraft propellers. These products were designed, built, and tested prior to the existence of PROP_DESIGN. The PROP_DESIGN example input files are based on information found on the internet. Thus, the PROP_DESIGN example designs may or may not be similar to the actual product designs.

 

Two additional examples are provided in the reference information folder. The examples are intended to show how PROP_DESIGN integrates into vehicle design projects. The examples are described below. The parts in black are where the cargo and/or passengers would go.

VTOL Example (with fixed thrust vectoring nozzles):

Below is an example of a VTOL aircraft. The ducted fans are shown in light blue. The thrust vectoring nozzles are shown in white. VTOL aircraft will be more efficient than helicopters and quadcopters. They will also be able to travel at much higher speeds. This is due to the air flow into the blades. An axial flow orientation is ideal.

 

VTOL aircraft are much less efficient than traditional aircraft. All VTOL have a lift-to-thrust ratio of one. Wings made with NACA 65A009 airfoils have a lift-to-thrust (i.e. L/D) ratio of 27.5. So VTOL aircraft should only be used when absolutely necessary.

Hovercraft Example:

Below is an application of a diffuser. Moreover, a diffuser was used to create static pressure for the plenum chamber of a hovercraft. The diffuser is shown in gray. The ducted fans are shown in light blue. The plenum chamber is shown in white.

 

The VTOL and hovercraft examples use the same fans. The hovercraft example uses half the fans of the VTOL example (3 out of 6 fans). Thus, the hovercraft example uses half the power of the VTOL example. The hovercraft example can lift 4.33x the weight of the VTOL example, while only using 25% of the thrust (1 out of 4 fans). This comes with one major limitation, hovercrafts can only float inches above the ground.

 

The hovercraft example has a lift-to-thrust ratio of 17.3. Traditional aircraft are more efficient than hovercraft. Wings made with NACA 65A009 airfoils have a lift-to-thrust (i.e. L/D) ratio of 27.5. Traditional aircraft are about as efficient as a typical car or truck. Cars and trucks have a lift-to-thrust ratio of 33.3.