After performing initial optimization studies it became obvious that the 15.5 ounce payload favored an engine displacement of 0.049 cubic inches, so the installed weight and shaft power are fixed to the values appropriate for a Cox TD 0.049 engine. The flight phases depicted in figure 2 are simulated by modeling the MA V as a point mass with thrust, lift, and drag forces acting on it during flight. Standard flight mechanics equations for climb, cruise, and descent flight are used to predict the MA V's performance in each phase of the mission. A genetic algorithm developed by the MLB Company was used to solve the constrained optimization problem. This method is a new technique that combines a simplex polytope method with an asexual genetic method to produce a hybrid search scheme that converges faster than standard genetic algorithms yet does not rely explicitly on gradient information in the search.
Constraints are automatically satisfied by a penalty weighting scheme that is invisible to the user.
Any constraint based numerical optimizer could be used to solve this problem, the genetic approach was the most convenient tool for the author to use. The method appears to converge more quickly than in reality because the internal simplex iterations are not plotted here. Aircraft size versus optimizer generation Figure 5. The MDO method has shown what size and aspect ratio aircraft is optimal for the mission, but does not yield any information on the configuration details. The aircraft has five basic controls, elevator, aileron, flap, throttle, and camera switch.