Mohammad Mashud

Numerical analysis of vertical axis wind turbine

A model for the aerodynamic evaluation of a vertical-axis wind turbine (VAWT) to improve its torque characteristics has been analysed. VAWT is more promising especially in areas with frequent light winds. This paper represent a numerical analysis of the aerodynamics performance on the straight blade fixed pitch VAWT (3 blades) based on the NACA 0018 airfoil. A solid modelling software ANSYS FLUENT which is linked to a finite volume Computational Fluid Dynamics (CFD) is used for the calculation of rotor performance. Gambit software is used to create 2D model of the turbine and the mesh which is generated in Fluent for numerical iterate solution. The Unsteady Reynolds averaged Navier-Stokes equation is used for the investigation of general effects on the performance of several geometry characteristics of two-dimensional airfoils. The RNG k-epsilon model is adopted for the turbulence closure. For proposed rotor analysis, flow field characteristics are investigated at different values of tip speed ratio and also the dynamic quantities such as rotor torque co-efficient and power co-efficient for a constant free stream velocity for 9 m/s which correspond to Reynolds numbers based on chord length of 2.6×105. The VAWT has an inherent unsteady aerodynamic behaviour due to the variation of angle of attack with the angle of rotation, perceived velocity and consequentially Reynolds number. This approach is necessary for having a numerical analysis at low computational cost and time.

Design and implementation of a Y-copter: Aerobatic version

In this present era of globalization, Unmanned Aerial Vehicle (UAV) has become one of the greatest innovations of technology due to its tremendous capability of rendering numerous tasks such as surveillance, data transfer, package delivery, instant medic etc. This paper illustrates the scenario of developing a Vertical Take-Off and Landing (VTOL) Radio Controlled (RC) 3-rotor UAV or on the contrary, a Y-shaped tricopter. A tricopter has two rotors that are spinning in opposite directions but there is a rotor left who produces torque that tries to spin the tricopter. Because of this, a rear servo was used to tilt the rear rotor to compensate this torque in the same manner a helicopter tail rotor does. The advantage of this solution is more yawing agility in comparison to multicopters with even amounts of rotors. KK 2.1.5 LCD board was used as the flight control board in which a host of multirotor craft types were pre-installed. At the heart of the KK 2.1.5 is an Atmel Mega644PA 8-bit AVR RISC-based microco...

Design and construction of an airfoil with controlled flap

For modern aircrafts maneuvering control and reduction of power loss is a matter of great concern in Aerodynamics. Separation of airflow over the wings of aircraft at high angle of attack or at other situations is a hindrance to proper maneuvering control. As flow separation increases drag force on the aircraft, it consumes excess power. For these reasons much effort and research has gone into the design of aerodynamic surfaces which delay flow separation and keep the local flow attached for as long as possible. One of the simple and cost-effective way is to use a hinged flap on the wing of the aircraft, which lifts and self-adjusts to a position dependent on the aerodynamic forces and flap weight due to reversed flow at increasing angle of attack. There is a limitation of this kind of process. At very high angles of attack, the reversed flow would cause the flap to tip forwards entirely and the effect of the flap would vanish. For recovering this limitation an idea of controlling the movement or rotation of the flap has been proposed in this paper. A light surface was selected as a flap and was coupled to the shaft of a servo motor, which was placed on a model airfoil. For controlling the angle of rotation of the motor as well as the flap arbitrarily, an electronic circuit comprising necessary components was designed and applied to the servo motor successfully.For modern aircrafts maneuvering control and reduction of power loss is a matter of great concern in Aerodynamics. Separation of airflow over the wings of aircraft at high angle of attack or at other situations is a hindrance to proper maneuvering control. As flow separation increases drag force on the aircraft, it consumes excess power. For these reasons much effort and research has gone into the design of aerodynamic surfaces which delay flow separation and keep the local flow attached for as long as possible. One of the simple and cost-effective way is to use a hinged flap on the wing of the aircraft, which lifts and self-adjusts to a position dependent on the aerodynamic forces and flap weight due to reversed flow at increasing angle of attack. There is a limitation of this kind of process. At very high angles of attack, the reversed flow would cause the flap to tip forwards entirely and the effect of the flap would vanish. For recovering this limitation an idea of controlling the movement or rotation...