Hover performance of a twin-rotor test model in terms of rotor overlap sweep, blade collective pitch, and blade tip speedwasexaminedexperimentally.The experimental setup consisted of two three-bladed rotors (tandem rotor configuration) with a diameter of1,220 mm and constant chord of 38 mm, giving a blade aspect ratio of 16.05. The blades were of a rectangular planform with NACA 0012 cross-sect...

The main advantage of tail-sitter unmanned aerial vehicle (UAV) are introduced. Three design solutions of rotor tailsitter lift system of UAV have been presented and the respective control strategies and characteristics of three solutions are also analyzed in the paper, through the related experiments the design of twin-rotor lift system is verified, and its feasibility is proved. The character...

The development and application of a software package for the design of twin screw compressors is presented in this paper. The package can be used to calculate the rotor profile, geometrical characteristics, thermodynamic performance, forces on rotor, rotor deflection and cutter shape. A user-friendly interface and some powerful post-processing programs are also included in the package. The app...

This paper deals with open-shaft twin-screw refrigeration compressors in the 10 175 m3/h (10 100 CFM) range. Applications for such compressors are, for example,external combustion engine heat-pumps and transport refrigeration. The twin-screw compressor concept is discussed from following view-points; operational mode and rotor housing design drive arrangement bearings lubricants cooling volume ...

In this paper, a fuzzy logic controller approach is presented for twin rotor multi-input-multi-output (MIMO) system in order to improve the control of pitch and yaw motions under hovering conditions. Twin rotor MIMO system resembles a helicopter model in some common aspects like cross coupling of pitch and yaw motions. The proposed approach is compared with another control strategy by simulatio...

This paper proposes a new technique of using Axial Flux Induction Machines (AFIMs) for wind energy conversion systems. The Power Generation by wind is found to be enhanced by using a Twin Rotor Axial Flux Induction Machine (TRAFIM). By using Axial Flux Induction Machines, the gear box ratio can be reduced. The Single air gap and TRAFIM have been mathematically modeled in the environment of MATL...

This paper presents a parameter study for optimum rotor geometrical parameter combinations of a refrigeration helical twin screw compressor with four commonly used lobe combinations and five different length/diameter ratios and wrap angles. The volumetric and indicated efficiencies of the compressor are important. So also are other factors such as rotor deflection, bearing load, bearing life an...

An optimisation procedure for twin screw compressor design is described, which is based on an analytical algorithm for rotor profile generation combined with a differential model of the fluid flow and thermodynamic processes within the machine. Rotor profiles are generated from a rack which have both stronger female rotor lobes and higher displacement. Compressors thus designed have higher deli...

Interest in system identification especially for nonlinear systems has significantly increased in the past few decades. Soft-computing methods which concern computation in an imprecise environment have gained significant attention amid widening studies of explicit mathematical modelling. In this research, an adaptive neuro-fuzzy inference system (ANFIS) network design is deployed and used for m...