Reducing rotor aerodynamic noise is an important challenge in helicopter design. Active flap control (AFC) on rotors effective reduction method. It changes the segment airfoil shape, load distribution, and wake path of flow by adding trailing edge flaps (TEFs). Although AFC easily simulated, relevant experiments have not been widely conducted due to test technical problems limited financial sup...

As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight materia...

some physical properties such as geometrical, gravimetrical, frictional and aerodynamic features of seeds of desi chickpea and its splits were studied at a moisture content of 8.2 and 9.0% w., respectively from north-western of iran. geometrical and gravimetrical properties including the average length, width, thickness, the geometric mean of diameter, sphericity, 1000-seed weight, unit weight,...

This paper presents the aerodynamic design and economical evaluation of a 200 kW site specific wind turbine for the province of Semnan in Iran. By designing site specific wind turbines, the cost of energy which is calculated out of the annual energy production and also the cost of manufacturing the rotor are minimized. The aerodynamic design is based on the well-known blade element momentum...

This paper presents a new practical autopilot design approach to acceleration control for tail-controlled skid-to-turn (STT) missiles. The approach is novel in that the proposed parametric affine missile model adopts acceleration as the controlled output and considers the couplings between the forces as well as the moments and control fin deflections. The aerodynamic coefficients in the propose...

This report has been produced in order to address aerodynamic characteristics and stability and control issues relating to hypersonic vehicles that are deemed to be significantly different from those of the conventional (subsonic or supersonic) air vehicles. In particular we have addressed issues that are relevant to stability and control of hypersonic vehicles. This report should add to the ex...

in this work, harmony search meta-heuristic optimization algorithm has been developed for aerodynamic shape optimization problem for the first time. the aerodynamic shape, which has been investigated, is an airfoil with parces method for its shape parameterization. the problem was minimization of aerodynamic objective function using inverse design method and the objective function has been the ...

with speed increasing in high-speed trains, due to limitations of other types of brakes, aerodynamic brake has become an important braking method. in this task to make better use of brake’s panel different configurations are examined and the best panel shape which provides the reasonable drag coefficient is introduced. the results of simulations are carried out with the computational fluid dyna...

A recent focus on revolutionary aerodynamic concepts has highlighted the technology needs of general aviation and personal aircraft. New and stringent restrictions on these types of aircraft have placed high demands on aerodynamic performance, noise, and environmental issues. Improved high lift performance of these aircraft can lead to slower takeoff and landing speeds that can be related to re...

In this paper, a nonlinear model of the underactuated six degrees of freedom (6 DOF) quadrotor helicopter was derived based on the Newton-Euler formalism. A new nonlinear robust control strategy was proposed to solve the stabilizing and path following problems in presence of external disturbances and parametric uncertainties. The proposed control structure consist of a sliding mode control base...