The on-going debate regarding the merits of large versus small aircraft carriers raises several issues concerning the ability of various ship configurations to support sea based air operations. One such issue is the q...
The on-going debate regarding the merits of large versus small aircraft carriers raises several issues concerning the ability of various ship configurations to support sea based air operations. One such issue is the question of the relative seakeeping performance of ship alternatives. In an effort to shed some light on the matter, a comparative seakeeping assessment of nine air capable ships covering a wide range of size and hull form was performed. An evaluation of the impact of aircraft and ship motion limitations on sea based air operations and a comparison of the relative ability of the ships to conduct air operations while in a seaway are presented. The specific air operations considered are launch, recovery, and support of aircraft. The ships evaluated are CVN-71, CVA-67 (MR), CVV, LHA-1, VSS-D, DDV-2, DDV-1D, DD-963, and SWATH-6. These ships have the combined capability to operate Vertical Takeoff and Landing (VTOL), Conventional Takeoff and Landing (CTOL), Short Takeoff and Arrested Landing (STOAL), and Short Takeoff and Vertical Landing (STOVL) type aircraft. Results indicate that seakeeping performance generally degrades with decreasing displacement, that SWATH-6 performance is the least degraded, that elevator wetness can be an important degrader for ships with lower freeboards, that roll motion can be an important degrader for ships under 60,000 tons, and that percent time of operation is strongly dependent on the prevailing wave and wind environment.
Guided by the example of gauge transformations associated with classical Yang-Mills fields, a very general class of transformations is considered. The explicit representation of these transformations involves not only...
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Guided by the example of gauge transformations associated with classical Yang-Mills fields, a very general class of transformations is considered. The explicit representation of these transformations involves not only the independent and the dependent field variables, but also a set of position-dependent parameters together with their first derivatives. The stipulation that an action integral associated with the field variables be invariant under such transformations gives rise to a set of three conditions involving the Lagrangian and its derivatives, together with derivatives of the functions that define the transformations. These invariance identities constitute an extension of the classical theorem of Noether to general transformations of this kind. An application to the case of gauge fields demonstrates the existence of two distinct types of conservation laws for such fields.
The finite element and spectral methods are applied to two-dimensional bound state problems. A comparison of the spectral method, which requires a global basis set expansion of the wave functions, and the finite eleme...
The Benjamin-Ono equation is shown to admit a two-parameter family of Miura transformations, leading to a proof that the equation has an infinite number of conserved densities. Linearized equations are derived from a ...
The Benjamin-Ono equation is shown to admit a two-parameter family of Miura transformations, leading to a proof that the equation has an infinite number of conserved densities. Linearized equations are derived from a special case of the transformation.
We consider the evolution of packets of water waves that travel predominantly in one direction, but in which the wave amplitudes are modulated slowly in both horizontal directions. Two separate models are discussed, d...
It has been observed by Miura that the solutions of the modified Korteweg-deVries equation can be mapped into those of the Korteweg-deVries equation. In this note we show that all of the solutions of the former, decay...
IT is the purpose of this letter first to point out that several independent lines of evidence seem to indicate that the ‘intercloud medium’ does not exist in its usually quoted state with density≳0.1 cm−3and temper...
IT is the purpose of this letter first to point out that several independent lines of evidence seem to indicate that the ‘intercloud medium’ does not exist in its usually quoted state with density≳0.1 cm−3and temperatureT∼104K. Rather, a hot, tenuous medium (n≲10−2cm−3,T∼106K) seems more consistent with observations in the neighbourhood of the Sun. That such might be the situation has been previously suggested (see refs 1 and 2). A mechanism for producing such a medium has been proposed by Cox and Smith3. Second, this letter points out several implications of such a “missing intercloud medium” on the large-scale structure of spiral galaxies.
In a paper published in Tellus several years ago (Faller, 1960) it was pointed out that under certain experimental conditions flow injected through a slot in the eastern boundary of a rotating bounded basin resulted i...
In a paper published in Tellus several years ago (Faller, 1960) it was pointed out that under certain experimental conditions flow injected through a slot in the eastern boundary of a rotating bounded basin resulted in an unexpected eastern boundary current.
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