[en] Evolution of the stagnation point pressure and of the azimuth theta sub(N) corresponding to the minimal value of the pressure in function of Reynolds and Hartmann number. The drag coefficient variations are studied in a field marked by 93<=Re<=11,600 and 0<=M<160

[en] Soap bubbles were used for visualizing flows. The tests effected allowed some characteristics of flows around models in blow tunnels to be precised at mean velocities V₀<30/s and for a Reynolds number Re<5.10⁵. The velocity of a bubble is measured by chronophotography, the bulk envelope of the trajectories is also registered

[en] The MHD flow with aligned fields at infinity past a body in the far wake approximation is considered. In the case where two wakes, upstream and downstream, are present, by studying them separately (resp. as a coupled system) they are unstable (resp. stable) for both steady and unsteady small perturbations

[en] The patent refers to a pressure-head probe yielding more exact average values than current devices for the dynamic pressure varying over the cross-section of a flow to be measured by means of an integrated interpolation probe, and which therefore also allows more exact flow rate measurements of a fluid. The probe consists of an outer tube containing an inner tube with about half its diameter, sewing as an interpolation probe. This double tube is introduced as a diameter into the pipe containing the fluid to be measured ('medium pipe') until it reaches the opposite wall. The inner tube, which has only half the length, will then extend up to the middle axis of the medium pipe. The outer tube contains several borings, counter directed to the flow, on at least two diameters of the medium pipe, but no borings in the middle, i.e. on the axis of the medium pipe. The inner tube has only one lip-shaped opening at the end. The dynamic pressures taken up by the external borings are averaged within the outer tube; the mean pressure is picked up by the miner tube as an interpolation probe and led to the outside by this tube. Forming the difference with respect to a measurement of static pressure gives an index for the flow rate at this moment. The double probe for the dynamic pressure and a gange for measuring the static pressure are introduced together by a flange welded into the medium pipe. The double probe an be removed through a stuffing box and/or is rotatable. (HP)

[en] We analyze the problem of fluid flow in a bifurcating structure containing random blockages that can be removed by fluid pressure. We introduce an asymmetric tree model and find that the predicted pressure-volume relation is connected to the distribution Π(n) of the generation number n of the tree's terminal segments. We use this relation to explore the branching structure of the lung by analyzing experimental pressure-volume data from dog lungs. The Π(n) extracted from the data using the model agrees well with experimental data on the branching structure. We can thus obtain information about the asymmetric structure of the lung from macroscopic, noninvasive pressure-volume measurements

[en] This paper presents a brief review of the theory and observations of the solar wind. The success of simple fluid models is contrasted with the lack of understanding of the detailed microphysics on which such fluid theories are, or should be, based. (orig.)

[en] In the present paper, we focus on the flow computation of a low head Propeller turbine at a wide range of design and off-design operating conditions. First, we will present the results on the efficiency hill chart prediction of the Propeller turbine and discuss the consequences of using non-homologous blade geometries for the CFD simulation. The flow characteristics of the entire turbine will be also investigated and compared with experimental data at different measurement planes. Two operating conditions are selected, the first one at the best efficiency point and the second one at part load condition. At the same time, for the same selected operating points, the numerical results for the entire turbine simulation will be compared with flow simulation with our standard stage calculation approach which includes only guide vane, runner and draft tube geometries.

[en] This paper sets forth concepts on capillary properties in the rocks of the earth which might be helpful in understanding the production of fluids from tight rocks. In underground gas storage, especially in aquifers, it became important to understand caprocks - the mechanism by which gas is held indefinitely in the earth. From studies of low permeability rocks, interest was developed in the fluid content of all rock layers of the earth. Capillary effects which are controlling in most caprocks are very significant in fluid flow in all low permeability rocks containing two phases

[en] The effect of a variable magnetic field on the rheological properties of non-Newtonian fluids is evaluated. Bituminous pitch oils were analyzed by recording the flow curves Q.Q(Δp) - the dependence of the volumetric flow rate on the pressure gradient - with and without a field. The results obtained indicate that variable magnetic fields can produce obvious changes in the rheological properties of bituminous pitch oils, although they are nonmagnetoactive and practically electrically nonconducting

[en] A flowmeter with a conical rotor is described resting with the cone-shaped shell on a conical wall of the housing for non-flowing medium and lifting from the wall for flowing medium; in addition, it has slots in the cone-shaped shell. By a special shape and retaining slots it is achieved that the rotor exactly follows the changes of the flow velocity. (RW)