This paper proposes novel Fuel Cell Auxiliary Power Unit (FCAPU) for J150+ aircraft application. The primary version of APU in J150+ aircraft is a gas turbine Auxiliary Power Unit (APU) which is based on gas turbine jet engine but in the suggested FCAPU, the generated electrical power is achieved from chemical energy with higher efficiency. The Solid Oxide Fuel Cell (SOFC) technology is used to...

Wing morphology and flight kinematics profoundly influence foraging costs and the overall behavioral ecology of hummingbirds. By analogy with helicopters, previous energetic studies have applied the momentum theory of aircraft propellers to estimate hovering costs from wing disc loading (WDL), a parameter incorporating wingspan (or length) and body mass. Variation in WDL has been used to elucid...

For the purposes of development of a small and autonomously operated airship, a need to create a model of its propelling and motion has arisen. Being described within this paper, the model defines the requirements that are imposed to motors, propellers and the airship's controlling system. The model is based on a typical design of a small airship, that consists of two main propellers, being pla...

In aeronautics and shipbuilding fields quality control of propellers is an obligatory step, a hard task up to some years ago: the shape of each blade has to be measured with high accuracy and referred to a global frame. Specific CMMs were used in the past to perform such complex analyses. When propellers were mounted on ships on dry dock, inspections became nearly impossible to be performed. In...

Guidance and control of aircraft in the landing phase imposes extra pilot work loads, hence application of automatic landing control systems is of great importance. In this study automatic landing control systems are introduced and an optimal landing control system is designed. The control system performance criteria are based on minimum control effort. The designed system is simulated for a tr...

Abstract This study introduces the simulation of a tri-rotor contra-rotating propeller for thrust force and hover lift efficiency during vertical take-off. Vertical take-off or landing is method used by many aircraft makes vehicle more convenient easier to use. The second rotor revolved in opposite direction first third rotors. proposed multi-rotor system has NACA 0012 untwisted symmetric airfo...

A numerical study of the magnetic induction equation has been performed on von Kármán type flows. These flows are generated by two co-axial counter-rotating propellers in cylindrical containers. Such devices are currently used in the von Kármán sodium (VKS) experiment designed to study dynamo action in an unconstrained flow. The mean velocity fields have been measured for different configuratio...

Molecular evolution has focused on the divergence of molecular functions, yet we know little about how structurally distinct protein folds emerge de novo. We characterized the evolutionary trajectories and selection forces underlying emergence of β-propeller proteins, a globular and symmetric fold group with diverse functions. The identification of short propeller-like motifs (<50 amino acids) ...

Abstract: In recent decades, micro air vehicles driven by electric propellers have become a hot topic, and developed quickly. The performance of the vehicles depends on the rotational speed of propellers, thus, improving the accuracy of rotational speed measurement is beneficial to the vehicle’s performance. This paper presents the development of a soft sensor for the rotational speed measureme...