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Measurements of the entire pressure field around a two-dimensional bubble rising in an incipiently fluidized bed are reported. Above the center of pressure line, the field is Laplacian and reasonably well described by Davidson's theory. The pressure wake is closed. It extends for 12 bubble radii below the stagnation point and four radii on either side of the vertical axis of symmetry.

The present paper relates to experimental researches on rudder performance utilizing a free running, self-propelled model.Hardover to hardover steering tests have been carried out on four different balance ratios including the optimum one estimated by turning tests, and it is known that the balance ratio must be selected so as to prevent the abnormally large positive torque which may occur when the rudder is steered from port to starboard.An interpretation for the complicated rudder performance during the turning tests have been tried using the results of behind tests and free model tests. As the results, the resonable values for normal force coefficients have been provided through considering the change of slip ratio of propeller and drift angle of ship, but it remains some problems to be investigated for the center of pressure.

Free flight dynamic stability measurements indicate that boundary layer transition has no perceptible effect

The author discussed the performance of open rudder, particularly the effect of angular velocity of steering in Reports Nos. 1 & 2 of this series of experiments, and described, in Reports Nos. 3 -& 4, the effect of propeller race on the rudder performance. Therefore, in Report No. 5, the present report, the author principally discusses the experimental results pertaining to the effects of wake and propeller as the remaining problem, and lastly he mentions the practical formulae applicable to the normal force of rudder and the position of the centre of pressure, integrally considering Reports Nos. 1-5.The following points were made clear as the results of model experiments of the rudder placed behind the ship and ship's propeller.(1) When the propeller is located in.froht of the rudder, the effect of wake can be presumed by considering the mean effective wake fractions within the propeller actuator disc, and when the propeller is not in front of the rudder, by considering the nominal wake fractions around the rudder.(2) As to the effect of propeller race on the normal force of rudder, it is the function of the slip-ratio of the propeller just the same as in the case of open propeller, and its increment ratio is in proportion to 1.5 power of the slip-ratio, but the coefficient is greater than in the case of open propeller.(3) In the case of the rudder behind the right-handed turning propeller situated at the stern, when normal force is zero, the helm angle shifts to the port in many cases, though slightly, but in the case of a great rudder angle, normal force indicates an almost equal value for both port and starboard. The position of the center of pressure alone is affected by unsymmetry of the upper and lower portions in the distribution of wake.(4) Regarding the composite effects on the normal force of rudder located at the stern, the effect of wake and that of race mutually offset and in an ordinary propelling condition, there is shown an increase of an equal degree, or by 10-20%, as compared with normal force working on open rudder at the time of an equal velocity to the ship's speed.Lastly, the practical formulae for the normal force and the center of pressure of ruddes in the single screw vessel are given, and the calculated values of the pressent formula were compared to the measured results of the actual vessel.

Translational forces on Mariner 5 stemming from attitude control system, determining trajectory for scientific and operational purposes

An analytical solution to the problem of the lubrication of slider blocks of fixed wedge angle and finite width is presented. The method of solution is by the separation of variables which yields results conveniently shown in curve form illustrating the various slider properties. The analysis is not encumbered by the requirement of numerical or graphical methods of evaluation as in the case of Michell, and is similar in nature to the solutions of Muskat, Morgan, and Meres wherein explicit analytical expressions are derived for the slider characteristics. The solutions appear in the form of convergent series. The present analysis illustrates the manner by which the separation of variables in Reynold's Equation may be effected, completes the solution of the resulting eigenvalue problem, and shows the formulation of the expressions for load capacity, frictional resistance, center of pressure, coefficient of friction, and rates of flow. Typical pressure hills are shown as well as approximate flow patterns thr...

The effect of pad-surface curvature on load capacity, center of pressure, and fluid friction is determined using Reynolds' differential equation in hydrodynamic lubrication theory. A dimensionless parameter which is a function of the magnitude of curvature is introduced. Families of curves are obtained and presented in a manner similar to Norton (1). The results indicate the practical use of pad curvature for centrally pivoted pads where the variation in fluid viscosity from pad inlet to outlet is negligible.

It has been observed experimentally by Hama and discussed theoretically by Weinbaum that effects of the fast expansion and consequent lip shock at the shoulder of a supersonic base or downstream-facing step can be quite appreciable at high Mach number. Hama found that the lip shock can be much stronger than has been assumed. He also drew attention to characteristic humps or peaks in the pressure distribution on the reattachment surface; these, he showed, could be attributed to secondary waves directed toward the surface from the point of interaction of the lip shock with the main recompression shock. Scherberg and Smith have also drawn attention to the possible strong effects connected with a lip shock. In this note, we report some further observations of the occurrence of this phenomenon, and its elimination by a small modification at the shoulder to alleviate the fast expansion there.

Cone-conical-frustrum configurations meeting center of gravity requirements for higher hypersonic lift-drag ratios in axisymmetric manned spacecraft