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Works: 139 works in 143 publications in 1 language and 150 library holdings
Publication Timeline
Viscous Effect on Ship Wave Resistance( Book )

1 edition published in 1983 in English and held by 3 WorldCat member libraries worldwide

Topics contained in this report are: (1) The methods of conformal mapping and analytic continuation are applied to obtain slender-body centerplane distributions; and (2) Three closed-form approximations to the double-integral 'near field' term in the Havelock Green function are derived. An application to centerplane source distributions for ship-wave problems is discussed
Calculation of the viscous resistance of bodies of revolution by A Nakayama( Book )

1 edition published in 1973 in English and held by 3 WorldCat member libraries worldwide

The flow in the tail region of a body of revolution is a complex one since there the boundary layer often grows to a thickness many times the local radius of the body and there results a strong interaction between the boundary layer and the external potential flow. The influence of making simplifying assumptions concerning the flow in this region in conventional drag-calculation methods is discussed, and assessed by incorporating a method which takes into account the effects of the thick axisymmetric boundary-layer near the tail in an approximate manner. It is shown that this modification leads to a drag-calculation method which gives consistently accurate prediction of the viscous resistance of a wide variety of bodies of revolution. (Author)
Effects of waves on the boundary layer of a surface-piercing body by Frederick Stern( Book )

2 editions published between 1985 and 1987 in English and held by 2 WorldCat member libraries worldwide

The boundary-value problem associated with the boundary-layer development on a surface-piercing body is formulated in a rigorous manner in which proper consideration is given both to the kinematic and dynamic boundary conditions and to the deformation of the potential-flow free surface within the boundary layer. Simplifications that are appropriate for small amplitude waves are then investigated. The flow flow field in the neighborhood of the body-boundary-layer/free-surface juncture is divided into five regions and order-of-magnitude estimated for each region are provided. Of particular interest is the body/free-surface boundary layer in the region very close to the free surface in which the free-surface boundary conditions have a significant influence. In this region, it is shown that, for laminar flow, the parameter Ak/e (where Ak is the wave-steepness parameter and e = delta/L is the nondimensional boundary-layer thickness) is an important parameter for characterizing the flow. Different solution regimes are identified depending on the magnitude of Ak/e. In particular, for Ak/e sufficiently large such that the free-surface boundary conditions have a significant influence a consistent formulation requires the solution of the partially-parabolic Navier-Stokes equations. For turbulent flow, these conclusions cannot be reached with the same degree of certainty due to the present uncertainties in turbulence modelling, especially when a free surface is present. Numerical results are provided for the idealized geometry of a combination Stokes-wave/flat-plate. Keywords: Wave/boundary layer interaction; 3-D boundary layer; Ship boundary layer
Further investigations on components of ship resistance final report by L Landweber( Book )

2 editions published between 1974 and 1975 in English and held by 2 WorldCat member libraries worldwide

The accomplishments during the eleventh year of research on components of ship resistance, supplementing that reported in IIHR Report No. 162 on the first 10 years, are summarized. These include the derivation of a more exact formula for calculating the viscous drag of a ship model from wake-survey measurements, a refinement of a procedure for determining wave resistance from surface-profile measurements, studies of the effect of the wake on wave-resistance measurements, and some contributions to the problem of correcting resistance measurements for the influence of tank boundaries
Viscous-inviscid interaction with higher-order viscous-flow equations by Frederick Stern( Book )

2 editions published between 1986 and 1987 in English and held by 2 WorldCat member libraries worldwide

The partially-parabolic, or parabolised, Navier-Stokes equations for laminar flow, and the corresponding Reynolds equations for turbulent flow, are coupled with an inviscid-flow solution procedure to develop a viscous-inviscid interaction method which can be used three-dimensional flows which cannot be treated by means of the classical boundary-layer equations. Potential applications of such a higher-order matching procedure include thick layers (wakes, wall jets), solid-solid and solid-fluid corners. This report provides a detailed overview of the approach for general 3-D flows and presents the results of applications to some simple test cases. The Reynolds equations are derived in nonorthogonal curvilinear coordinates, with velocity components along the coordinate directions, using vector techniques. This approach differs from the commonly-used tensor method but serves to establish a connection with the more familiar boundary layer methods. The k-epsilon model is used for turbulent flows. The partially-parabolic viscous-flow equations are solved using an implicit finite-difference scheme and the SIMPLER algorithm for pressure-velocity coupling. The inviscid-flow solutions are obtained with a conforming panel, source-panel method. Interaction between the viscous and inviscid regions is accounted for using the displacement -body concept
Suspended sediment modeling of dredge-disposal effluent in the GREAT-II study reach( Book )

1 edition published in 1980 in English and held by 2 WorldCat member libraries worldwide

The objectives of this study were to: (1) Collect field data on suspended solids and turbidity during two dredge disposal operations on the Mississippi River; (2) Check the utility of the Schubel and Carter (1978) model for adequately describing the observed field data and modify, if possible, to reflect river conditions; (3) Examine other models available to describe the observed field data, including the numerical, computer solution of Weschler and Cogley (1977) (such models can be used to rapidly generate a number of simulations covering a spectrum of conditions expected in the Mississippi River); and (4) Develop a convenient, analytical solution for the prediction of suspended solids concentrations caused by hydraulically dredged sediment and compare the model results to field measurements. The scope of this modeling effort includes the utilization of existing dredge disposal mathematical models, both analytical and numerical, as well as the development of a new model. The new model is specifically derived for continuous nonpoint source, sidebank disposal type of operations such as commonly practiced in the upper Mississippi River. Suspended solids concentrations are predicted. This research grew out of a larger dredging study by a multi-departmental, multi-disciplinary consortium called the Great River Environmental Action Team, GREAT II. The GREAT II study reach of the Mississippi River stretches from Guttenberg, Iowa to Saverton, Missouri
Experimental study of the wavemaking of horizontally-oriented vorticity in a wake by A Swain( Book )

1 edition published in 1974 in English and held by 2 WorldCat member libraries worldwide

Towing-tank experiments were conducted in order to investigate the wavemaking of horizontally-oriented vorticity in a wake. It was found that the amplitudes of the surface disturbance, measured with three capacitance wires, were about one tenth of those generated by a ship model of the same length and Froude number. Furthermore, the wave resistance was about one percent of that obtained for a Series-60 model of the same wetted-surface area. (Author)
GREAT II Upper Mississippi River (Guttenberg, Iowa to Saverton, Missouri) Water Quality Work Group Appendix( Book )

1 edition published in 1980 in English and held by 2 WorldCat member libraries worldwide

The study programs and recommendations of the three GREAT Teams will be brought together into a river management strategy for the entire Upper Mississippi River. The goal of the study is to present to Congress and the people a river resource management plan that is, above all, realistic - a plan that is technically and economically sound, socially and environmentally acceptable, and capable of being put into action within a reasonable period of time
Orthogonal coordinate systems for three-dimensional boundary layers : with particular reference to ship forms by Touvia Miloh( Book )

1 edition published in 1972 in English and held by 1 WorldCat member library worldwide

The problem of choosing orthogonal, curvilinear, coordinate systems for use in boundary-layer calculations on arbitrary three-dimensional bodies is considered in some detail. A general method for the practical evaluation of the various geometrical properties of the coordinates occurring in the three-dimensional boundary-layer equations is described. A particular coordinate system which appears to be the most convenient one for ship hulls is then proposed and analyzed further
Coralville water quality study annual report : water year October 1, 1975 to September 30, 1976 by Donald B McDonald( Book )

1 edition published in 1979 in English and held by 1 WorldCat member library worldwide

The Coralville Reservoir Water Quality Project was initiated in 1964 and has continued without interruption since that time. The purpose of the study has been the determination of the effects of a flood control reservoir on the chemical and biological characteristics of its parent river. Samples were collected from the Iowa River upstream from the reservoir; at Johnson County Road W-8 (formerly '0'); from the top, mid-depth and bottom at the reservoir at the Mehaffey Bridge downstream from the Lake MacBride spillway; and from the Iowa River at two points downstream from the reservoir about one mile below the Coralville dam and at the University of Iowa Water Treatment Plant. During the current water year, samples were collected on a weekly basis and analyzed for temperature, conductivity, turbidity, dissolved oxygen, Ph, carbon dioxide, alkalinity, ammonia and orthophosphate. All other parameters, including plankton, were determined on a twice monthly basis
Fully Developed Periodic Turbulent Pipe Flow. Part 2. The Detailed Structure of the Flow( Book )

1 edition published in 1983 in English and held by 1 WorldCat member library worldwide

Detailed model study of pump-approach flows for the Lake Chicot pumping plant by Tatsuaki Nakato( Book )

2 editions published in 1977 in English and held by 1 WorldCat member library worldwide

A 1:24 Froude-scale model of the proposed Lake Chicot Pumping Station was constructed and utilized to identify and to correct hydraulically objectionable features of the flows in the pump sumps. The model tests showed that the flows from the plant forebay generally enter the individual pump bays with a strong transverse component of velocity and produce an intense captive eddy on the lee side of each pump-bay partition wall. The transverse velocity resulted from geometric constraints imposed on the plant configuration. In order to achieve better pump approach-flow conditions trash racks with relatively deep vertical bars which functioned as turning vanes were proposed. A 1:10-scale sump model then was built to test for model-scale effects in the trash-rack tests, and an extensive study was conducted to obtain an improved sump configuration which would minimize any vortex-related problems in and around pump suction bells. The modified sump configuration has small clearance between the pump bell and sump back-wall; converging sidewalls; and a floor mounted splitter plate (vortex breaker) beneath the pump. (Author)
An investigation of the total sediment load by Emmett M Laursen( Book )

1 edition published in 1957 in English and held by 1 WorldCat member library worldwide

Effect of wake on wave resistance of a ship model by Marguerite Moreno( Book )

1 edition published in 1975 in English and held by 1 WorldCat member library worldwide

For the purpose of resolving the question of the influence of its wake on the wavemaking resistance of a ship, the total, viscous and wavemaking resistance of a Series 60 ship model were measured with the wetted surface first smooth, and then rough. It was found that the wave resistance was significantly less with the rough surface, implying that viscous effects should not be neglected in the development of higher-order wave theory. Since the wake-survey method was used to determine the viscous resistance, the opportunity was taken to compare the results with roughness with the values obtained by calculating the boundary layer on the rough 'equivalent' body of revolution, with satisfactory agreement
Viscous flow over ship sterns by V. C Patel( Book )

1 edition published in 1985 in English and held by 1 WorldCat member library worldwide

When this research project was initiated in October 1980, it was evident that neither reliable calculation methods nor a comprehensive set of data existed for the description of the complex viscous flow over the stern and in the wake of the ship hull. The 1980 SSPA-ITTC Workshop on Ship Boundary Layers (Larsson, 1981) had indicated that all available methods for the calculation of thin boundary layers broke down, for a variety of reasons, in the stern region. At about the same time, the author (Patel, 1980) reviewed previous experimental investigations in wake flows for the Standard Conferences on Complex Turbulent Shear Flows and concluded that there was not a single set of reliable and detailed data for three-dimensional stern and wake flows which could be used as a test case for the assessment of calculation methods for such flows. This investigation was therefore undertaken with three specific objectives: (1) To develop promising three-dimensional thin boundary-layer calculation methods for application to arbitrary ship hulls and assess their limitations; (2) To develop a calculation procedure for the flow over the stern and in the wake of the ship; and (3) To conduct a comprehensive, wind-tunnel experiment on a ship double-model to document, in detail, the mean flow and turbulence in the thick stern boundary layer and the near wake. Additional keywords: Stern flow; Turbulent flow; Navier Strokes equations

1 edition published in 1963 in English and held by 0 WorldCat member libraries worldwide

In order to supplement the limited data so far discovered, the evaluation of the drag coefficients of various head forms under cavitating conditions at various angles of yaw, from the measured values of the pressure distribution, was undertaken. The aforementioned pressure distributions for zero angle of yaw were published by the Iowa Institute of Hydraulic Research, in 1948. Eight of the head forms included in these first tests were selected for a further study of pressure distribution under cavitating conditions at angles of yaw and the results were published in 1962. The latter also included pressure distribution measurements at zero angle of yaw. The results obtained for the drag coefficients of the various head forms at several yaw angles are presented and compared with the directly measured values for the drag at zero angle of yaw available in the literature. No data on direct measurements of drag at angles of yaw have been found
Interaction and impact of floating bodies by A. T Chwang( )

1 edition published in 1992 in English and held by 0 WorldCat member libraries worldwide

On the basis of two 1983 OPNAV instructions, S34705A entitled 'U.S. Navy Policy Regarding Arctic Polar Region' and S3470.6 entitled 'U.S. Navy Warfare Program', the U.S. Navy is preparing to operate its surface ships at high latitudes on a routine basis in support of the nation's Maritime Strategy. In addressing these operating requirements, the U.S. Navy must evaluate the ability of its surface ships to fulfill their mission when operating near the ice edge in the marginal ice zone, and when entering an ice covered port with icebreaker assistance. As the Arctic has become a principal strategic location, knowledge and prediction of sea-ice conditions and the ability to cope with them have become essential to the U.S. Navy. The long-term goal of our research project is to investigate the hydrodynamic interactions, including central and oblique impact, between two floating bodies, or between a floating body and a fixed body. The floating body is usually an ice floe, and the fixed body is an offshore structure. Our near-term objectives are to develop a rationally formulated, computer-based analytical model of far-field ice-floe trajectories and near-field hydrodynamic interactions between floating ice floes and offshore structures. The offshore structures considered in the present study would be assumed to have the shape of a circular cylinder. The ice floes would have the shape of a rectangular block, a rectangular cylinder, a circular cylinder, a circular disk, or a sphere. The analysis would be based on the equations of planar motion of an ice floe under the action of external forces due to wind, fluid viscosity, fluid inertia, and the nonuniformity of the flow field due to the presence of the offshore structures
Analysis of Sacramento River bend flows, and development of a new method for bank protection by A. Jacob Odgaard( )

1 edition published in 1982 in English and held by 0 WorldCat member libraries worldwide

This study includes an investigation of analytical models for the description of flow and bed charactersitics in a bend of the Sacramento River, California; and a study of a proposed new technique for bank protection. Existing models for the prediction of the steady-state transverse bed profile in channel bends are reviewed; and alternative models are developed and validated. The new models predict the transverse bed slope to-vary linearly with d/r (the ratio of depth, d, to radius curvature, r) and almost linearly with the sediment-particle Froude number. Equations for the transverse variation of depth-averaged' velocity and mean-grain size also are developed, which, together with the equations for the transverse variation of depth, can provide a guide to the depth of bed erosion and depth-averaged velocity near the outer bank of river bends. It is shown, theoretically and by a physical model, that short, vertical, submerged vanes installed at incidence to the channel axis in the outer banks of a river-bend channel significantly reduce the secondary currents and the attendant undermining and high-velocity attack of the outer bank. The effect of the vanes on the secondary flow is estimated by a simple torque calculation using the. Kutta-Joukowski theorem. A design relation for the van spacing is derived by equating the torque, about the channel centroid, produced by the flow curvature to that resulting from the lateral force exerted on the vanes. The relation is verified in an idealized, physical model of the mentioned bend of the Sacramento River, Calif
Fluid and Thermodynamic Characteristics of Compressible Recoil Mechanism( )

1 edition published in 1979 in English and held by 0 WorldCat member libraries worldwide

Fluid dynamic aspect of recoil mechanisms is studied with simple one dimensional analysis as well as two dimensional numerical analysis. Method and procedure for experimental simulation is given. Full scale and reduced scale simulation is analyzed for its advantages and disadvantages. A new numerical scheme called 'finite differential' method is developed to solve the two dimensional unsteady Navier-Stokes equation. The new method utilizes the local analytical solution of the total problem. The solution of the problem is obtained by assembling the local analytic solution. The method is shown to be capable of solving flows with high Reynolds numbers
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English (23)