【正文】 ailing and leading edges for both halves of the airfoil. The number of control points can be changed within the call script that runs the optimizer. The design vector is fed into the objective function, which fits a spline curve through these “handle” points and the tangencies provided at LE and TE (see Figure 6). The spline curve is converted into data points and saved as the airfoil coordinate input file for XFoil. 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 . 7 0 . 6 0 . 5 0 . 4 0 . 3 0 . 2 0 . 1Co ntro l “ h an d l e ” po in tsSmoo th spl i ne curveCo nstra i n re gio ns Figure 6 Il。 14 Landing distance was calculated using a summation of approach distance, flare distance, ground roll distance and a two second frictionless roll at stall speed to account for the time before the pilot applies the brakes. Approach distance was calculated using Raymer’s equation : ? ?bc TRobstaclec hhS limtan ? ?? Equation 25 hobstacle and γclimb have been previously discussed. hTR was calculated using Raymer’s equation : ? ?? ?bcTR Rh limc o s1 ??? Equation 26 where R is calculated using Raymer’s equation : stallVR ?? Equation 27 where Vstall is a design parameter equal to 57 kts and is explained in further detail later. Flare distance was calculated using Raymer’s equation : DLWTST 1?? Equation 28 where T/W is the thrust to weight at idle speed (20%) and L/D is the lift to drag ratio with full flaps which is assumed to be 5 based upon the aerodynamic analysis/engineering judgment. Ground Roll distance is calculated by using Raymer’s equation : ???????? ?????????? ??? 2ln2 1 iAT TAG VKK KKgS Equation 29 where g is the gravity constant, Vi is the initial speed (assumed to be stall speed at touchdown). KA and KT are calculated using the following 2 equations: ???WTKT Equation 30 ? ?? ?202 LDLA CKCCSWK ?????? ?? Equation 31 All of the above values have been previously discussed except for μ which was estimated to be based upon Raymer’s Table [10]. Best range cruise speed was calculated using Raymer’s equation which is seen above in Equation 11. Best range cruise distance was calculated using equation of Raymer: ???????????? fibhp p WWDLCR ln550 ? Equation 32 Where ηp is the propeller efficiency, Cbhp is the BSFC, L/D is the minimum drag lifttodrag ratio and Wi/Wf is the weight ratio of the segment. The minimum drag lifttodrag ratio is calculated Team V。 8 Sizing Sizing and Carpet Plot Code Sizing of the Barn Owl was done through the use of carpet plots based on a weight fraction approach and its implementation in a Matlab script. The script was used to automatically generate the carpet plots with constraint lines, so that the lightest weight feasible design point could be determined. Since an existing engine was selected for the Barn Owl, as described below, fixedengine sizing was used. Thus, carpet plots sizing the aircraft with different aspect ratios over a range of wing loadings were used to set the design. The script uses an iteration scheme which assumes an initial guess for gross takeoff weight (GTOW), then calculates GTOW based upon that guess. It then iterates the guessed weight until the two weights are within % of each other (approximately lbs). Within the code, GTOW was calculated using the following equation: ????????????????????0001 WWWWWWWefp a y l o a dc r e w Equation 1 The empty weight fraction ????????0WWe was calculated by first calculating all of the ponent weights based upon chapter 15 of Raymer [10]。= Preliminary Design Review Stephen Beirne Charlie Rush Miles Hatem Zheng Wang Chris Kester Brandon Wedde Jim Radtke Greg Wilson AAE 451 Aircraft Design Final Report Team V 27 April, 2020 Team V。 7 Design Mission Based upon this team’s QFD analysis, as presented in the system requirements review, it was determined that to be petitive in the chosen market the aircraft would need to have a range of 600 nautical miles and cruise near 8000 ft. From this the design mission was formulated. Figure 2 – Design Mission Table 2 – Design Mission Legend A Taxi 14 minutes F Climb to divert altitude (2020 ft MSL) B Takeoff roll at sea level G 45min loiter / divert C Climb to cruise (8000 ft MSL) H Descend to sea level D Cruise at 150 KTAS I Landing Roll E Descend to sea level J Taxi to hanger The mission begins with an estimated 14 minute taxi to the runway. Next, the plane will begin its takeoff roll at a runway located at sea level. The mission has been designed from sea level since it is a good benchmark from which to measure altitude. After takeoff the plane will climb at 700 fpm to its cruising altitude of 8000 ft MSL and cruise at that height at a speed of 150 KTAS. After cruising the specified 600 nmi, the aircraft will descend back down to sea level. Just before touching down, it will then climb to a divert/loiter altitude of 2020 ft MSL. It will then either spend 45 minutes loitering in pattern or diverting to an alternative airport as per FAR fuel requirements for IFR flight. Finally it will descend again to sea level, land, and taxi back to the hanger. Team V。 13 In Equation 19 W/S, ρ, ρsl (same as ρ), CL_climb, g, and W are as previously discussed. hobstacle is the height of an obstacle to be cleared during takeoff (50 ft). G is calculated using the equation: 0s in 1m i nlim ??????? ???? ? WDWTG bc ?? Equation 20 where T/W is the thrust to weight ratio, D is the drag force during climb, and W is the GTOW. All of these values have been previously discussed. U was calculated using the equation: m a x_ ??? LCU Equation 21 where CL_max is assumed to be