The current work presents the numerical prediction method to determine small-scale propeller performance. The study is implemented using the commercially available computational fluid dynamics (CFD) solver, FLUENT. Numerical results are compared with the available experimental data for an advanced precision composites (APC) Slow Flyer propeller blade to determine the discrepancy of the thrust c...

When an isolated magnetar with magnetic dipole field B ∼ 10 G moves at high velocity (v > 10 cm s) through the ISM, its transition into propeller effect driven spin-down may occur in less than 10 years. We propose that the nearby neutron star RXJ1856.5-3754 is such a magnetar, and has spun down by the propeller effect to a period greater than 10 sec within ∼ 5 × 10 years. This magnetar scenario...

Design and manufacturing of a high performance micro-hydro-kinetic turbine is discussed in the present paper. The main goal is manufacturing an equipped experimental model of hydro-kinetic turbine with highest energy absorption from water current. A multi-shape ducted turbine comprised of a multi-part diffuser was manufactured that can be converted to many experimental models for studying vario...

Surface-piercing propellers have been widely used in light and high-speed vessels because of their superior performance. One of the major steps in propeller selection algorithm is the determination of thrust as well as torque hydrodynamic coefficients. For the purpose of simplifying design and selection procedure, some relations are presented for determining hydrodynamic coefficients in some st...

In this paper a recently reported four-quadrant nonlinear thrust controller for marine propellers is applied to the velocity control of an underwater vehicle. The controller, designed for fixed pitch electrically driven propellers, is based on a shaft speed control and employs an estimate of the propeller torque loss. A simulation study is performed in order to compare the presented approach wi...

Accuracy is the key issue in the precision forging. Geometric and dimension errors are the two significant defects found in most of near net or net shape manufacturing process. It becomes more critical for complex part such as an AUV propeller blade. In this study, geometric error was quantified by comparing the blade profile obtained from nominal geometry of the blade and the profile construct...

As small rotorcraft grow in capability, the possibilities for their application increase dramatically. Many of these new applications require stable outdoor flight, necessitating a closer look at the aerodynamic response of the aircraft in windy environments. This paper develops the equations of motion for a single-propeller test stand by analyzing the blade-flapping response of a small-stiff p...

We follow the approach used by Davies and Pringle (1981) and discuss the trans-sonic substage of the propeller regime. This substage is intermediate between the supersonic and subsonic propeller substages. In the trans-sonic regime an envelope around a magnetosphere of a neutron star passes through a kind of a reorganization process. The envelope in this regime consists of two parts. In the bot...

A literature review, a datasheet review, and in-house experimental data were used to obtain a real-world comparison between bio-mimetic pectoral fins and traditional propeller-based thrusters. Only power consumption, forward thrust, and propulsive efficiency are compared. Scaling trends for both propulsion forms are discussed. Traditional thrusters are determined to be more efficient than curre...

This paper focuses on the modelling and simulation of unsteady sheet cavitation in marine propeller flows. In the first part of the paper, the mathematical model based on potential flow theory is introduced and the numerical scheme is derived. The novelty of the presented calculation method refers to the unsteady partial sheet cavitation model which has been implemented into the in-house panel ...