 |
AGATE DESIGNAerodynamics |
| EXECUTIVE SUMMARY | The VenTure features
a high-lift airfoil to allow an easy break from the water surface on takeoff
at low angles of attack. The GA(W)-2 airfoil section, also known
as the LS(1)-0413, has high lift at low angles of attack (Figure
5) and a high lift-to-drag ratio, (L/D), at its cruise lift coefficient,
CLcruise. Table 2
lists the airfoil selections for the wing, horizontal and vertical tails,
and sponson. The dimensions of the wing and flaps are found in Table
3.
Parasitic drag, CDO, was determined using the equivalent flat-plate area calculated from the VenTure's average skin friction coefficient, wetted area, and wing area. The value obtained, CDO = .0227, is comparable to most single-engine, four-seat general aviation aircraft. The wing’s taper ratio and washout angle were determined based on a comparative study of wing shape effect on the Oswald efficiency factor. The wing geometry was then optimized to give a low induced drag coefficient and a wing Oswald efficiency factor of 99%, as shown in Table 4. Vortex Lattice Method (VLM) calculations were used to determine the induced drag due to body effects of the VenTure. Using the VLM code, VLM4997, the total Oswald efficiency of the VenTure is estimated to be 88%. The effect of flap deflection is shown in Figure 6, the graph of lift coefficient versus angle of attack for various flap configurations. Another benefit of the GA(W)-2 is the gradual transition into stall at high angles of attack. Figures 7 and 8 present the airfoil’s drag polar and lift-to-drag ratio curves. Details of the VenTure's complete aerodynamic analysis can be found in Appendix G. |
