Browsing by Author "Boyle, W P"

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    A towed submersible
    (1973) Dunkley, William Rae; Boyle, W P
    One way to continuously scan the sea would be to tow a submarine vehicle that would cycle vertically in the water between set depths. Its period of vertical oscillation would be short compared with the changes in parameters to be measured, in this case long internal waves. It would carry continuously recording depth and temperature measuring instruments; if possible storing the results on a magnetic tape or paper drum or else transmitting the data to the towing vessel. It could be designed so that it was relatively independent of ship speed and self-contained so that it could operate unattended for long periods of the normal oceanographic surveys require regular stops for geological core samples to be taken or for sampling reversing bottles to be cast, and during these moments the vehicle could be hauled aboard and its recording sheets or power sources renewed as necessary. Accordingly a specification was determined in consultation with members of the Oceanography Department of the University for a suitable towed body (Table 1.1). Initially it was to carry temperature measuring devices, but it should have the possibility of extending this to carry instruments to measure pH, conductivity, etc.. The only published work at present concerning such a device is by Glover (2), who is developing an undulating plankton recorder for long distance towing with an oscillating wave length of 20 km. It is not very appropriate to make direct comparison with Glover's work since there local instabilities are damped out during the long, slow oscillations, whereas for a device with a much shorter wave period such local perturbations crucially affect the performance. A device with a relatively short undulation period for intense data collection would be a major advance in oceanographic recording techniques, and one that could have a wide variety of commercial applications.
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    Aspects of laminar free convection from a vertical plate
    (1972) Gryzagoridis, Jasson; Boyle, W P
    The thesis is comprised of a number of aspects pertaining to the phenomenon of laminar free convection from a vertical plate. A survey of literature is presented which brings out the fact, that the phenomenon although it has been investigated to a large extent, still gives rise to widespread dispute and uncertainties which need careful examination. An analytical approach is presented showing that the hydrodynamic boundary layer is equal to the thermal boundary layer. In the past it was simply assumed to be so, in order to limit the computations, and the assumption was justified by the excellent agreement between calculations and experimental data. An analysis is presented showing the analogy existing between the Grashof and Reynolds numbers, as it is expected in the case of low velocities and considerable temperature differences, i.e. in free convection. An extensive experimental investigation pertaining to average heat transfer rates from a vertical plate at low Grashof numbers is presented and provides the necessary evidence in a much disputed region. It is shown conclusively that as far as average heat transfer rates are concerned, the agreement with the already accepted relationship can be extended to Grashof numbers as low as 10.
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    A study of projectile motion on impact with thin aluminium plates
    (1975) Pearson, Giles Christopher; Boyle, W P; Dutkiewicz, Ryszard Karol
    A new technique has been developed to examine projectile motion on impact with thin aluminium plates. A brief review of the field of penetration is given to show where the need for the present research arises. This is followed by an examination of alternative methods which could be used to determine penetration behaviour of projectiles and a discussion of their respective merits. Any impact phenomenon of elastic bodies is accompanied by inherent vibrations. Because of the greater sensitivity of the method used by the author over previous methods, vibrations set up in the projectile sensing mechanism played a very significant role in the penetration process. To take account of the vibration phenomenon, recourse was made to Masket's (1949) work which enables the motion of the centre of mass of the projectile to be determined from a knowledge of the motion of any point on the projectile. The new technique has many advantages over previous methods, the main one being the simultaneous production of deceleration-time data as the projectile penetrates the target material. Although the data must still be processed to remove superimposed vibrations, it does not have to undergo the drastic smoothing process of double differentiation used in previous methods. Because of this, the overall characteristic shape of the deceleration-time plot is preserved.
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    Open Access
    A towed submersible
    (1973) Dunkley, William Rae; Boyle, W P
    One way to continuously scan the sea would be to tow a submarine vehicle that would cycle vertically in the water between set depths. Its period of vertical oscillation would be short compared with the changes in parameters to be measured, in this case long internal waves. It would carry continuously recording depth and temperature measuring instruments; if possible storing the results on a magnetic tape or paper drum or else transmitting the data to the towing vessel. It could be designed so that it was relatively independent of ship speed and self-contained so that it could operate unattended for long periods of the normal oceanographic surveys require regular stops for geological core samples to be taken or for sampling reversing bottles to be cast, and during these moments the vehicle could be hauled aboard and its recording sheets or power sources renewed as necessary. Accordingly a specification was determined in consultation with members of the Oceanography Department of the University for a suitable towed body (Table 1.1). Initially it was to carry temperature measuring devices, but it should have the possibility of extending this to carry instruments to measure pH, conductivity, etc.. The only published work at present concerning such a device is by Glover (2), who is developing an undulating plankton recorder for long distance towing with an oscillating wave length of 20 km. It is not very appropriate to make direct comparison with Glover's work since there local instabilities are damped out during the long, slow oscillations, whereas for a device with a much shorter wave period such local perturbations crucially affect the performance. A device with a relatively short undulation period for intense data collection would be a major advance in oceanographic recording techniques, and one that could have a wide variety of commercial applications.