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Showing 1 to 16 of 16 for “"propeller performance"”.
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Using Single Propeller Performance Data to Predict Counter-Rotating Propeller Performance for a High Speed Autonomous Underwater Vehicle
The use of counter-rotating propellers is often desirable for aerospace and ocean engineering applications. Counter-rotating propellers offer higher peak efficiencies, better off-design performance, and roll control capabilities. But counter-rotating propeller matching is a difficult and complex …
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Propeller performance analysis using lifting line theory
Propellers are typically optimized to provide the maximum thrust for the minimum torque at a specific number of revolutions per minute (RPM) at a particular ship speed. This process allows ships to efficiently travel at their design speed. However, it is useful to know how the propeller performs …
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Design of a non-axisymmetric stator for improved propeller performance
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering and Dept. of Mechanical Engineering, 1987.
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Computational improvements to predict propeller performance at off design conditions
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.
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A study on the efficient numerical analysis for the prediction of full-scale propeller performance using CFD
… limited number of full-scale studies with ship propellers have been conducted due to the limitation of computational resources and computation time. There are two methods for efficient full-scale numerical analysis; (1) a method of using large non-dimensional wall-normal distances (y +) and (2) …
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Post stall propeller behavior at low Reynolds numbers
Limited data exists for propeller and wind turbine post stall aerodynamics. Post stall aerodynamics was observed in small propellers at low Reynolds numbers. First, performance data (thrust, power, and efficiency) of set variable pitch propellers was acquired in a wind tunnel. The propellers were 6 …
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Fuel consumption prediction methodology for early stages of naval ship design
… propulsor and propulsion plant to ensure best performance and to comply with imposed design requirements. Thus, this work will address three main aspects of the fuel consumption equation: -- Ship's resistance is calculated using a computational fluid dynamics simulation of the vessel in calm …
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Propeller design and analysis for a small, autonomous UAV
… was performed to design and analyze a "pusher" propeller for use by a small, expendable, autonomous unmanned aerial vehicle (UAV) whose mission was to descend from 30,000 feet to sea level at an approximately constant descent rate over a 3-hour mission duration. The entire propeller design …
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Design and Analysis of Low Reynolds Number Marine Propellers with Computational Fluid Dynamics (CFD) Transition Modeling
Small-scale marine propellers operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of …
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Design and Development of a High-Performance Quadrotor Control Architecture Based on Feedback Linearization
… thesis is to outline the development of a high-performance quadrotor control system for an AscTec Hummingbird quadrotor using direct motor speed control within a Vicon motion capture system environment. A Ground Control Station (GCS) acts as a user interface for selecting flight patterns and …
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Development of computational and experimental techniques to Investigate the effect of biofouling on ship hydrodynamic performance
Hull and propeller roughness can be caused by various factors such as mechanical causes, chemical and electrochemical processes (e.g. corrosion), and finally the colonisation of biofouling, which is often the most critical. The associated economic and environmental problems include increases in …
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Experimental investigation of non-uniform flow past propellers
… of non-uniform flow past a 1.615 foot, 3-bladed propeller was conducted in the Virginia Tech 6 foot by 6 foot Stability Wind Tunnel. The free stream velocity was 44.5 ft/sec and the propeller rpm 1400. A screen disk consisting of two circular meshes, one 15 inches in diameter and the other 5, …
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Performance and slipstream characteristics of small-scale propellers at low Reynolds numbers
The low Reynolds number effects of small-scale propellers were investigated. At the Reynolds numbers of interest (below 100,000), a decrease in lift and an increase in drag is common making it difficult to predict propeller performance characteristics. A propeller testing apparatus was built to …
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Structural design of shape-adaptive composite marine propellers
… alloy is the most common material for ship propellers but, more recently, composite materials have been used in propeller construction. One of the advantages of the use composite materials for ship propellers is that they allow the possibility of shape-adaptability. A shape-adaptive …
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The development of intelligent hull forms of large ships for energy efficient transportation
… (ESD) in order to improve the hydrodynamic performance and fluid flow of a vessel. These two areas are not new to the industry and have been investigated using various methods, including computational fluid dynamics (CFD) procedures. The use of CFD for ship performance analyses is becoming …