A practical online optimization scheme is developed for performance optimization of an electrical aircraft propulsion system. The goal is to minimize the power extraction of the propulsion system for any given thrust value. The online optimizer computes the optimum pitch angle of a variable pitch propeller by minimizing the power of the system for a command thrust value. This algorithm is teste...

Optimization of noisy non-linear problems plays a key role in engineering and design problems. These optimization problems can't be solved effectively by using conventional optimization methods. However, metaheuristic algorithms such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) seem very efficient to approach in these problems and became very popular. The efficiency of these ...

This paper presents high-fidelity and simplified computational fluid dynamics modeling approaches within an optimization framework for compound rotorcraft configurations with rotor/propeller aerodynamic interactions. Simulations of axial-flight ducted propeller a rotor/wing test case are first presented to validate the in-house Helicopter Multi-Block 3 solver assess actuator disk/line models ma...

Tuned mass dampers (TMDs) systems are one of the vibration controlled devices used to reduce the response of buildings subject to lateral loadings such as wind and earthquake loadings. Although TMDs system has received much attention from researchers due to their simplicity, the optimization of properties and placement of TMDs is a challenging task. Most research studies consider optimization o...

in this paper, a stochastic cell formation problem is studied using queuing theory framework and considering reliability. since cell formation problem is np-hard, two algorithms based on genetic and modified particle swarm optimization (mpso) algorithms are developed to solve the problem. for generating initial solutions in these algorithms, a new heuristic method is developed, which always cre...

this paper proposes a new mixed integer programming model for multi-item capacitated lot-sizing problem with setup times, safety stock and demand shortages in closed-loop supply chains. the returned products from customers can either be disposed or be remanufactured to be sold as new ones again. due to the complexity of problem, three meta-heuristics algorithms named simulated annealing (sa) al...

various synthesis methods have been proposed in the literature for reversible and quantum logic circuits. however, there are few algorithms to optimize an existing circuit with multiple constraints simultaneously. in this paper, some heuristics in genetic algorithms (ga) to optimize a given circuit in terms of quantum cost, number of gates, location of garbage outputs, and delay, are proposed. ...

Ducted propeller is a kind of special widely used in unmanned underwater vehicles, its flow characteristics and hydrodynamic noise are very important for marine environmental protection equipment concealment. The hybrid techniques based on the acoustic analogy theory adopted present study to calculate unsteady field sound ducted propeller. full scale filed hydro-acoustic sources propulsion syst...