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Showing 1 to 18 of 18 for “"Potential flow theory"”.
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Numerical Modeling of Lifting Flows in the Presence of a Free Surface
… model hydrodynamics problems involving lifting flows. The method employed to solve the problem is potential flow theory.</p> <p>Despite the fast evolution of computers and the latest developments in Navier-Stokes solvers, such as the Ranse methods; potential flow theory offers the possibility to …
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Tip leakage flow in a linear turbine cascade
… was performed to study the details of flow in the tip clearance gap of a linear turbine blade cascade. The cascade was designed and built to be geometrically similar to the earlier VPI&SU cascade; however, the new cascade also had a tip gap (2.1 percent of blade height) and two endwall …
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Application of Finite-State Wake Models to Rotors Re-entering Their Own Wake
… thrust was evaluated under assumptions of axial flow and potential flow theory. Results consist of computations of the inflow velocity for this case, along with comparison to closed-form, potential flow solutions for validation. The finite-state model is shown to converge with the closed-form …
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Optimal control theory applied to ship maneuvering in restricted waters
… this research is to apply modern optimal control theory to these maneuvering scenarios in order to show that helmsman may some day be replaced by modern controllers. The maneuvering equations of motion are cast in a linear state space framework, permitting the design of a linear quadratic (LQ) …
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Potential-flow Inflow Model Including Wake Distortion and Contraction
… models (derived from momentum theory) to full finite-state models derived from potential flow theory by a formal Galerkin method. These models are widely used in industry, but still have some drawbacks that need to be remedied. These drawbacks include: 1.) lack of good …
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Numerical simulation of green water and resulting loads
… carried out in the present thesis. Green water flow and its impact load on the deck structure for a stationary FPSO and a moving FPSO with heave and pitch motions are investigated by a 2-D numerical simulation method. The simulations are carried out using a commercial software ANSYS FLUENT, to …
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Analysis of ship performance in deep and shallow waters using CFD
… waters, as well as shallow water ship flows. Most approaches used to predict the performance of a ship have typically relied on the assumptions inherent in potential flow theories, namely, the fluid is treated as inviscid and irrotational. In many cases, these are justifiable …
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AN EXPERIMENTAL AND NUMERICAL STUDY ON CAVITATION BUBBLE DYNAMICS AND ITS BIOMEDICAL APPLICATIONS
… using a boundary-element model based on the potential flow theory are conducted to complement these experiments, and also study the interactions between a cavitation bubble and a nearby quiescent air bubble. Lastly, a cavitation bubble interaction with a nearby elastic cell, as well as the …
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Response of a pendulum spar to 2-dimensional random waves and a uniform current
A linearized theory for the response of a circular pendulum spar in 2-dimensional waves and a uniform current is developed. The linear forces on the cylinder are predicted using an approximate potential flow theory for slender bodies. The dynamic equations are then amended to account for the wake …
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On the application of variational mechanics in modeling the flow around a cylinder in ground effect
For high Reynolds number flow over a cylinder near a flat moving surface, a potential flow model can be used to represent flow over the leading edge. However, the potential flow solution requires knowledge of the circulation around the cylinder. This circulation value can be found with an auxiliary …
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Added Mass and Vortical Impulse: Theory and Experiment
… is derived under the assumption of inviscid flow. In the present thesis, this decomposition is shown to be valid for viscous flows. The classical added-mass force, derived using (acyclic) potential flow theory, is superimposable onto the circulatory force regardless of the presence of a …
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High–fidelity numerical modelling of ocean wave energy converters
… spectrum, numerical wave tanks based on linear potential flow theory assume linear conditions (small wave amplitudes and body motions) and are computationally efficient tools for, e.g., early stage design. However, the linear assumptions are pushed beyond the limits of validity when large body …
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Time-domain second-order wave interactions with floating offshore structures
… value problem can be derived on the basis of potential flow theory. A recent time-domain approach is extended to simulate second-order hydrodynamic effects involving large floating structures which cannot be obtained by the conventional linear hydrodynamic theory. The method involves the …
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Exploring the Limits of Boundary Element Methods for Wave Energy Converter Hydrodynamics
… on the bounding surface. BEM is based on linear potential flow theory, which has assumptions (e.g., linear, incompressible, inviscid, and irrotational flow) that may decrease the accuracy of the hydrodynamic estimates in some conditions. Despite the limitations imposed by these assumptions, …
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Pressure Disturbance Upstream of the Boundary Layer Data System
… <p>Prior to viscous modeling with CFD, potential flow theory was used to compute the inviscid upstream pressure disturbance for a generic excrescence on a smooth surface. A Rankine oval was generated using superposition, and a MATLAB program was written to evaluate ovals of varying chord …
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Aerodynamic and Electromechanical Design, Modeling and Implementation Of Piezocomposite Airfoils
… element method and a panel method based on the potential flow theory for fluids. The second concept is a variable-camber thick airfoil with two cascading bimorphs and a compliant box mechanism. Using the structural and aerodynamic theoretical analysis, both variable-camber airfoil concepts are …
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Quantifying microbubble streaming and its applications
… and exciting ways in which to drive microfluidic flows. A simple and powerful flow actuation method involves the use of acoustically excited microbubbles. For ease of manufacture and flow control, setups have largely focused on microbubbles of semi-cylindrical shape, attached to a wall of the …
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Computer-aided design of tension structures
… been set up in order to validate the underlying theory and implementation of the beam elements. As tension structures often exhibit complex surface curvatures, a study of surfaces, their properties and behaviour is appropriate, and useful in the understanding of concepts applied in the design …