EFFECT OF AXIAL POSITION OF PROPELLER ON THE PROPULSION CHARACTERISTICS OF A SUBMERGED BODY OF REVOLUTION

1963 ◽  
Author(s):  
John L. Beveridge
Keyword(s):  
Axial Position ◽  
Body Of Revolution ◽  
Submerged Body

A System to Measure Turbulent Lengthscales on Submerged Bodies of Revolution

2017 ◽  
Author(s):  
Christopher J. Chesnakas ◽  
Daniel R. Cadel
Keyword(s):  
Laser Doppler Velocimetry ◽  
Arrival Time ◽  
Noise Removal ◽  
The Body ◽  
Doppler Velocimetry ◽  
Body Of Revolution ◽  
Sampled Data ◽  
Bodies Of Revolution ◽  
Submerged Body ◽  
Cross Correlations

A system has been developed to measure the turbulent lengthscales in the flow about a submerged body of revolution. The system consists of two Laser Doppler Velocimetry (LDV) probes mounted inside the body of revolution with the beams projected outside of the body through conformal windows. The measurement volumes of the two probes can be independently positioned within a plane perpendicular to the body axis. The probes are used to measure velocity time series at various spacings in the flow field. Auto- and cross-correlations are computed for each measurement pair, from which integral lengthscales are then found. Measurements are compared to canonical data from a turbulent free shear jet. In this paper, the system is described and its theory of operation detailed. Methods of computing the velocity correlations from the random-arrival-time LDV measurements are presented, and a new noise-removal scheme for non-uniformly sampled data is introduced. Six methods for calculating the integral lengthscale from autocorrelation data are reviewed, and the results discussed for the present jet data measured with LDV.

On the Accuracy of an Analytical Solution to Model Wave-Induced Loads on an Underwater Vehicle in Real-Time

2020 ◽  
pp. 1-18
Author(s):  
Joseph Klamo ◽  
Travis M. Turner ◽  
Colin Y. Cool ◽  
Kathryn I. Yeager ◽  
Young W. Kwon
Keyword(s):  
Analytical Solution ◽  
The Body ◽  
Body Of Revolution ◽  
Unmanned Underwater Vehicles ◽  
Submerged Body ◽  
Pitch Moment ◽  
Theoretical Assumptions ◽  
Disturbance Model ◽  
Wave Induced ◽  
Large Parameter Space

Abstract The accuracy of an existing analytical solution for modeling the linear, first-order wave- induced loads on a fully submerged body is investigated. The accuracy is assessed for the situation where the underlying theoretical assumptions are met and the sensitivity of the accuracy to these assumptions is also explored. The accuracy was quantified by comparing the analytical solutions to experimental measurements from a tow tank with wave generation capability. The assessment showed that when all the assumptions are met, the heave and surge forces are predicted quite accurately but the pitch moment is over predicted. The results also showed that the deeply submerged assumption is met as long as the body does not cause a disruption of the passing wave on the free surface. The slenderness and end face curvature assumptions are also quite relaxed and the curvature assumption only affects the pitch moment accuracy. The most stringent assumption appears to be the body-of revolution assumption which can cause all three loads to be predicted poorly. The analytical solution appears to be accurate over a large parameter space and could be incorporated as a wave disturbance model into a virtual environment used to develop control and autonomy of unmanned underwater vehicles.

Numerical Simulation of Accelerating and Decelerating Motion of a Submerged Body

2005 ◽  
Author(s):  
George Tzabiras ◽  
Vlasia Papadopoulou
Keyword(s):  
Numerical Simulation ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Time Dependent ◽  
Forward Speed ◽  
Body Of Revolution ◽  
Submerged Body ◽  
Volume Method

The present work deals with the numerical simulation of accelerating and decelerating motions of a submerged body of revolution, in order to investigate the influence of the thrust variation on the maneuvering characteristics. A finite volume method is adopted to solve the essentially 2D RANS, time-dependent equations in a body-fitted co-ordinate system. Two problems have been examined for a 50m body of revolution: (a) the stopping maneuver, i.e. crash stop from steady forward speed and then full astern and (b) full ahead at steady speed from rest and then full astern.

Optimal design of a high homogeneous and small-size shim coil for atomic spin gyroscope based on 0-1 linear programming

2020 ◽  
Vol 64 (1-4) ◽  
pp. 165-172
Author(s):  
Dongge Deng ◽  
Mingzhi Zhu ◽  
Qiang Shu ◽  
Baoxu Wang ◽  
Fei Yang
Keyword(s):  
Linear Programming ◽  
Power Consumption ◽  
Low Power ◽  
Optimization Design ◽  
Structural Parameters ◽  
Axial Position ◽  
Low Power Consumption ◽  
Optimal Method ◽  
Atomic Spin ◽  
Shim Coil

It is necessary to develop a high homogeneous, low power consumption, high frequency and small-size shim coil for high precision and low-cost atomic spin gyroscope (ASG). To provide the shim coil, a multi-objective optimization design method is proposed. All structural parameters including the wire diameter are optimized. In addition to the homogeneity, the size of optimized coil, especially the axial position and winding number, is restricted to develop the small-size shim coil with low power consumption. The 0-1 linear programming is adopted in the optimal model to conveniently describe winding distributions. The branch and bound algorithm is used to solve this model. Theoretical optimization results show that the homogeneity of the optimized shim coil is several orders of magnitudes better than the same-size solenoid. A simulation experiment is also conducted. Experimental results show that optimization results are verified, and power consumption of the optimized coil is about half of the solenoid when providing the same uniform magnetic field. This indicates that the proposed optimal method is feasible to develop shim coil for ASG.

PROBLEM OF INTERFERENCE OF AN OGIVAL BODY OF REVOLUTION WITH THE WIND-TUNNEL STING AND SPECIFIC FEATURES OF COMPUTING THIS PROBLEM

2011 ◽  
Vol 42 (3) ◽  
pp. 321-344 ◽  
Author(s):  
Sergey Mikhailovich Bosnyakov ◽  
Vladimir Viktorovich Vlasenko ◽  
Innokentii Aleksandrovich Kursakov ◽  
Sergey Vladimirovich Mikhaylov ◽  
Jurgen Quest
Keyword(s):  
Wind Tunnel ◽  
Body Of Revolution ◽  
Ogival Body

Fluidic Control of Asymmetric Forces on a Body of Revolution

2008 ◽  
Author(s):  
Philip Abramson ◽  
Bojan Vukasinovic ◽  
Ari Glezer
Keyword(s):  
Body Of Revolution ◽  
Fluidic Control
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