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Stratification and Heat Transfer in Lakes and Reservoirs
Published in James L. Martin, Steven C. McCutcheon, Robert W. Schottman, Hydrodynamics and Transport for Water Quality Modeling, 2018
James L. Martin, Steven C. McCutcheon, Robert W. Schottman
From Equation 17, at 6:00 a.m., the solar altitude α = 0.171 using horn angle ω = he, from which the optical air mass can be estimated () θam=(288−0.0065(212)288)5.256sin(0.171)+0.15((0.171)180π+3.855)−1.253=5.5
Antennas and Feed Systems
Published in J. C. G. Lesurf, Millimetre-wave Optics, Devices and Systems, 2017
Some care must be taken when designing or building feed horns which have a very steep flare angle or which have a large open end. As a field moves closer to the open end, the effective waveguide size increases and the cut-off frequencies for higher te (or tm) modes will fall below the signal frequency. Any small imperfections in the horn may then alter the field pattern, changing the behaviour of the antenna. Also, the field moving within the horn does not have a plane phase front (otherwise it would not spread out!). The mode inside the horn will tend to have a spherical phase front centred on the horn apex. Hence there may not be a perfect transfer of signal between the guide and horn modes. This problem becomes more severe if the horn angle is increased.
Pulse pressure loading and erosion pattern of cavitating jet
Published in Engineering Applications of Computational Fluid Mechanics, 2020
Although lots of studies have investigated the erosion behavior of the cavitating jet, the characteristics of erosion patterns and corresponding pressure loading pulsation are far from being understood. In the current work, we have investigated this problem across a wide range of stand-off distances and employed an organ-pipe nozzle with a constant horn angle to generate the cavitating jet. A series of numerical calculations were performed using the LES and VOF model to gain insight into the pressure pulsation on the erosion area and the cavitation clouds movement. The experimental setup and numerical model are described in Section 2, main results are shown and discussed in Section 3, and final remarks are given in Section 4.