Showing papers in "Journal of Basic Engineering in 1971"
TL;DR: In this article, a theory is developed from first principles which includes all the important physical processes which affect the frequency of the free oscillations of a gas bubble and the components of the damping: viscosity, thermal conduction in the gas, and acoustic radiation.
Abstract: : A theory is developed from first principles which includes all the important physical processes which affect the frequency of the free oscillations of a gas bubble. The components of the damping: viscosity, thermal conduction in the gas, and acoustic radiation are all determined. Numerical results for the damping are given for air bubbles in water. (Author)
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TL;DR: In this article, Fatigue crack propagation rates were obtained for 2024-T3 bare aluminum plates subjected to in-plane, mode I, extensional loads and transverse, mode II, bending loads.
Abstract: Fatigue crack propagation rates were obtained for 2024-T3 bare aluminum plates subjected to in-plane, mode I, extensional loads and transverse, mode II, bending loads. These results were compared to the results of Iida and Kobayashi for in-plane mode I-mode II extensional loads. The engineering significance of mode I-mode II fatigue crack growth is considered in view of the present results. A fatigue crack growth equation for handling mode I-mode II fatigue crack growth rates from existing mode I data is also discussed.
56 citations
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TL;DR: In this paper, the problem of an accelerating potential flow past a group of stationary circular cylinders is considered using the method of images, and the problem is formulated so that the number and location of the cylinders is arbitrary so long as there is no overlap between adjacent cylinders.
Abstract: The problem of an accelerating potential flow past a group of stationary circular cylinders is considered using the method of images. The problem is formulated so that the number and location of the cylinders is arbitrary so long as there is no overlap between adjacent cylinders. Inertial and lift coefficients are determined for several different cylinder arrangements. The inertial coefficient for a cylinder can vary in either direction from its single-cylinder value of 2.0. The controlling factors on this variation are the relative geometric position of the cylinder within the group and its distance from its neighbors. These same factors determine, as is expected, the lift coefficient values. In two example configurations, there is even a drag-type force generated on an individual cylinder in the potential flow.
50 citations
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TL;DR: In this article, the natural frequencies of two spherical bubbles as they oscillate near each other in water were theoretically studied, by taking account of surface tension, and on the assumption of the gas in the bubbles following the law of adiabatic change.
Abstract: : The natural frequencies of two spherical bubbles, as they oscillate near each other in water, was theoretically studied, by taking account of surface tension, and on the assumption of the gas in the bubbles following the law of adiabatic change. As a result, the present solution includes these solutions of Minneart, Richardson and Neppiras and Noltingk as particular cases. (Author)
TL;DR: In this paper, the anisotropy of fatigue crack propagation in hot rolled steel plate was studied for three orientations, viz, crack arrester, crack divider and short transverse.
Abstract: The anisotropy of fatigue crack propagation in hot rolled steel plate was studied for three orientations, viz, crack arrester, crack divider and short transverse. The dependence of crack growth rate on stress intensity factor was shown to be sensitive to the microconstituents present and their orientation relative to the fracture plane and direction. Generally, this dependence increased as the material toughness decreased and when the mechanical fibering was parallel to the fracture plane and direction. The macroscopic growth rates were considered as the summation of several macroscopic mechanisms, including striation formation and inclusion-matrix fracture.(Author)
TL;DR: In this article, a new boundary layer theory is developed which retains all elements of classical boundary layer theories, such as momentum thickness and wall shear stress, but introduces new concepts such as axial and tangential defect force thickness, a rotor exit-stator inlet "jump condition" and the importance of these concepts is demonstrated.
Abstract: The essential ingredient missing in existing prediction methods for the performance of multistage axial compressors is that which would account for the effect of end-wall boundary layers. It is, in fact, believed that end-wall boundary layers play a major role in compressor performance and the absence of an adequate theory represents a handicap to turbomachinery designers that might be likened to the handicap that designers of wings, for example, would face if Prandtl had not introduced the idea of a boundary layer. In this paper a new theory is developed which retains all elements of classical boundary layer theory; for example, we discuss variables such as momentum thickness and wall shear stress. However, the present theory introduces new concepts such as axial and tangential defect force thickness, a rotor exit-stator inlet “jump condition” and the importance of these concepts is demonstrated. Inherent in the derivation is an identification of the role of secondary flow and tip clearance flow. A proper means of matching the boundary layer calculations to conventional main stream calculations is suggested. Independent of empirical parametization it appears that the theory is capable of correctly modeling boundary layer blockage, losses, and end-wall stall. Near stall, the main stream-boundary layer interaction is very strong.
TL;DR: In this article, an integral method for the non-boundary-layer flow in laminar, radially inward through-flow of an incompressible Newtonian fluid between parallel corotating disks is presented.
Abstract: An integral method is developed for the three-dimensional, nonboundary-layer flow which occurs for laminar, radially inward through-flow of an incompressible Newtonian fluid between parallel corotating disks. The method is a forward-stepping procedure which forces satisfaction of integrals of the governing differential equations, plus boundary conditions, plus the governing differential equations at every radius. The velocity components are represented by polynomials of order N; the method is extendable with extraordinary ease to any value of N. It is reported that, with N = 8, the results agree very closely with results earlier obtained by a conventional finite-difference method and which agree with experiment. It is pointed out that the method presented is extremely conservative of computational time and might be adapted to many other problems.
TL;DR: In this article, the effects of cable stranding on vortex shedding frequency and transverse vibrations on the vortex formation behind cables have been investigated at Reynolds numbers 240 and 500 in the transition and irregular ranges of vortex shedding, for five bodies; a smooth circular cylinder and four cable models with different stranding characteristics.
Abstract: This technical brief reports the results of some initial experiments concerned with the effects of cable stranding on the vortex shedding frequency and the effects of transverse vibrations on the vortex formation behind cables. Measurements were made at Reynolds numbers 240 and 500 in the transition and irregular ranges of vortex shedding, for five bodies; a smooth circular cylinder and four cable models with different stranding characteristics.