Abstract: A methodology is presented for simulating turbomachinery blade rows in a multistage environment by deploying a standard 3D Navier-Stokes solver simultaneously on a number of blade rows. The principle assumptions are that the flow is steady relative to each blade row individually and that the rows can communicate via inter-row mixing planes. These mixing planes introduce circumferential averaging of flow properties but preserve quite general radial variations. Additionally, each blade can be simulated in 3D or axisymmetrically (in the spirit of throughflow analysis) and a series of axisymmetric rows can be considered together with one 3D row to provide, cheaply, a machine environment for that row.Two applications are presented: a transonic compressor rotor and a steam turbine nozzle guide vane simulated both isolated and as part of a stage. In both cases the behaviour of the blade considered in isolation was different to when considered as part of a stage and in both cases was in much closer agreement with the experimental evidence.Copyright © 1990 by ASME

Abstract: We present theoretical and experimental results on the stability and time-behaviour of instabilities in circular Couette flow with superimposed axial flow. Linear stability theory is used within the small gap approximation to explain the stability and dynamics of the instabilities in form of ring and spiral vortices. Ring vortices can travel only in the direction of throughflow. In contrast, spiral vortices can be obtained either in a steady state or time — dependent travelling in the direction or in opposite direction of the throughflow. The travelling direction depends on the ratio of the Taylor number to the throughflow Reynolds number. With throughflow as an initial condition a new secondary instability is found at high Taylor numbers.

Abstract: It is shown by means of a numerical model of the western Dutch Wadden Sea that the residual current velocity field cocnsists of a throughflow from one tidal basin to another and a field of residual eddies The first can be explained by the residual momentum balance which gives the driving force of the throughflow in terms of the tidal stress The latter is more easily understood from the vorticity balance in which bottom frictional generation and damping of vorticity, together with vortex stretching, explain most of the observed features Near the inlets the rediual eddy pattern has the shape of a highly distorted vorticity quadrupole

Abstract: Local and average heat transfer were measured for a system of multiple jets impinging on a moving permeable surface at which there may be throughflow. Multiple jets were confined by a hood, as is required industrially for thermal efficiency. Exhaust ports located symmetrically between the jet nozzles eliminated crossflow, otherwise a strongly detrimental effect. Impingement surface motion decreases average heat transfer, by 17% at industrially relevant values of the surface motion parameter, Mvs. Enhancement of impingement heat flux by throughflow is linearly additive. Expressed as ΔSt, this enhancement depends only on the throughflow parameter, Mus, with ΔSt/Mus = 0.17. For typical operating conditions, withdrawal as throughflow of only 10% of the jet flow increases mean Nusselt number by over 50%. Industrial design modeling for the potential process of combined impingement and throughflow drying of wet webs such as paper is demonstrated.

Abstract: Only a small part of the precipitation deposited on to terrestrial systems falls directly into surface waters, the bulk falling on to vegetated land surfaces. As the precipitation moves through the vegetation canopy its chemistry is modified, as a result of interactions with plant surfaces, before reaching the ground as throughfall and stemflow. The throughfall and stemflow waters form the input to soils where they are further modified by soil-solute interactions. Soil waters may enter streams directly as throughflow, surface flow or return flow or they may form the input to groundwaters in underlying drift deposits and bedrock. In the drift and bedrock the chemistry of percolating waters is influenced by solute-rock mineral interactions before forming the groundwater input to surface waters.

Abstract: The variable source area model of storm flow generation VSAS2 has been adapted to simulate snowmelt runoff in the Lac Laflamme forested basin, 80 km north of Quebec City. The model has been adapted to accept different water inputs according to topography, to factor the effect of lake water storage in the discharge hydrograph and to process 3 months of hourly data. To ensure convergence of the mathematical solution, the explicit form of flow equations included in VSAS2 has been transformed to use an iterative approach. Lysimeter measurements as well as outputs from the snowmelt temperature index model SNOW-17 were used as input data in the simulation. Results showed that low flows in early spring were well reproduced by the physically based model. However, all seasonal (1985, 1986 and 1987) peak flows were underestimated when all water input was considered to infiltrate. Observations on the site showed that the natural topographical drainage network was augmented in the spring by superficial concrete frost, pipe throughflow at the organic-mineral soil interface and snowpack basal ice layers. It was therefore necessary to use an infiltrability index to improve the model. Because it was closely related to the development of an impervious layer at the soil surface, the relative proportion of bare ground areas on the basin was also related to the rising of streamflow hydrographs. Thus values of snow cover areal extent were taken from SNOW-17 outputs and used as an index to the prevailing conditions of soil infiltrability on the basin. Results from VS AS2 were greatly improved, supporting the hypothesis of an important surface flow contribution during late snowmelt. The study underlined the necessity of further field investigations on the dynamics of infiltration processes into frozen soil.

Abstract: An apparatus is disclosed for measuring the throughflow of a body liquid, in particular an apparatus for measuring the flow of urine in urological function diagnostics. The apparatus comprises a collecting funnel connected to a tube, which can be suspended in a WC bowl. In the tube are two axially spaced transducers one for continuously determining the electrical conductivity of fluid flowing through the tube from the funnel and the other for determining the specific electrical conductivity of the liquid. An electronic evaluation system determines the throughflow of the liquid upon the basis of the values determined by the transducers.

Abstract: The apparatus has two purification stages (I, II) connected in series each having a circulation (2, 22) having a throughflow photoreactor (1, 21). Each throughflow photoreactor (1, 21) is differently dimensioned at least with respect to the total optical path length according to the initial transmission and the transmission change effected therein. The water to be purified is metered into the first circulation according to the transmission measured upstream of the throughflow photoreactor (1) and the transmission measured at the exit of the throughflow photoreactor. A feed pump (10, 13) for an oxidising agent forming oxygen free radicals under UV radiation at least in the first purification stage is controlled according to the initial transmission of the particular throughflow photoreactor.

Abstract: A rotating cavity with an axial throughflow of cooling air is used to provide a simplified model for the flow that occurs between adjacent corotating compressor discs inside a gas-turbine engine. Flow visualization and laser-Doppler anemometry are employed to study the flow structure inside isothermal and heated rotating cavities for a wide range of axial-gap ratios. G. rotational. Reynolds numbers, Reφ, axial Reynolds numbers, Rez, and temperature distributions.For the isothermal case, the superposed axial flow of air generates a powerful toroidal vortex inside cavities with large gap ratios (G > 0.400) and weak counter-rotating toroidal vortices for cavities with small gap ratios. Depending on the gap ratio and the Rossby number, e (where e ∝ Rez/Reφ), axisymmetric and nonaxisymmetric vortex breakdown can occur, but circulation inside the cavity becomes weaker as e is reduced.For the case where one or both discs of the cavity are heated, the flow becomes nonaxisymmetric: cold air enters the cavity in a “radial arm” on either side of which is a vortex. The cyclonic and anti-cyclonic circulations inside the two vortices are presumed to create the circumferential pressure gradient necessary for the air to enter the cavity (in the radial arm) and to leave (in Ekman layers on the discs). The core of fluid between the Ekman layers precesses with an angular speed close to that of the discs, and vortex breakdown appears to reduce the relative speed of precession.Copyright © 1990 by ASME

Abstract: The water-side connection of a central-heating boiler is to be designed in such a way that condensate formation owing to inflowing, cool return water is avoided. For this purpose, the return connection (9) leads into the upper, front region of the heating boiler, and to be precise in such a way that it is surrounded, with a forward-pointing extension (10), on all sides by a shaft (11) with a horizontal throughflow. Owing to the injection action, hot flow water is sucked through the shaft. A mixture of cool return water and hot flow water comes into contact with the boiler surfaces, with the result that condensate formation is prevented.

Abstract: In a vehicle heating device a portion of the outgoing-air flow only flows through a subregion of the heat exchanger and is accordingly subject to less temperature control. In the process, this portion of the outgoing-air flow penetrates the subregion of the heat exchanger essentially orthogonally with respect to the direction of throughflow of the other outgoing-air flow, which flows through the entire heat exchanger and is hence subject to more pronounced temperature control. As a result, a defined temperature layering can be obtained in a simple manner in the passenger compartment.

Abstract: A water jet pump which is connected to the water-inflow pipe of the toilet flushing means takes in used water during the throughflow of fresh water and thus makes it possible for the toilet flushing to take place by a mixture of fresh water and used water. The used water taken in by the water jet pump is located in a used-water storage tank which is arranged beneath the bathtub, washbasin or shower. When the used water flows out of the bathtub, washbasin or shower, the used-water storage tank located therebeneath is filled; excess used water flows via an overflow pipe into the drainage system as waste water.

Abstract: The discharge of suspended sediment and two solutes from the River Dart basin (46 km 2 ) have been analysed by correlation with different runoff components. The cascade tank model, developed by Suzuki et al. to simulate the hydrologic response of different soil horizons in Japanese basins in mountainous head-waters, proved appropriate for separating the hydrographs of the River Dart into direct runoff, throughflow and baseflow components. Multiple regression analysis has been used to reveal the contribution of different runoff components to the discharge of magnesium and nitrate ions

Abstract: An irrigation device for plant receptacles for cultivating walls of greenery has droplet receptacles which have an overflow in addition to their droplet opening. Combined with a water-storage means, it constitutes a very effective rainwater-retention device for the soil cultivation of facades with greenery. The droplet receptacles are integrated into the cultivated greenery at various levels. The irrigation device and the water-storage means are filled by a rapid water throughflow. The soil is wetted by the water running slowly out of the droplet receptacles.

Abstract: Throughflow theory has been limited in its applicability and in its accuracy by the fact that it has not historically been cast in a form that can account for the nonaxisymmetries that naturally arise in turbomachinery flow due to the presence of finite numbers of rotor and stator airfoils The attempt to circumvent this limitation by the introduction of an aerodynamic blockage factor has been demonstrated in earlier work to produce fundamental inconsistencies in the calculation, which lead to significant errors in the regions of the flow where the nonaxisymmetries are severe The formulation in Part I of the present work is a derivation of a system of throughflow equations for nonaxisymmetric flow A benchmark database is used in Part II to provide input to the calculation and to help identify the dominant terms It is demonstrated that the dominant effect of nonaxisymmetry is contained in two terms that relate the total pressure of the averaged flow to the mass-averaged total pressure It also is demonstrated that the present formulation produces a result that is more accurate than that obtained with the historical blockage-based formulation

Abstract: A system-theoretical approach, the input-output flow analysis, is applied to the study of water flow, protein metabolism and energy flow in human body: indices characterizing patterns of flow, that is, throughflow, total system throughflow, path length, cycling index and trophic position are calculated and discussed for flow-networks within human body. Cycling indices for energy-flow are zero and those for mass-flow are large; this tendency is also the case for ecosystems as systems-ecology shows. In this respect, a human body can be regarded as a “mini-ecosystem”. Trophic positions for mass-flow are larger than the numberings of compartment, showing also quantitatively the existence of intense cycling in mass-flow in human body.

Abstract: Detailed three-dimensional velocity distributions, corresponding to design and off-design operation, were measured in two differnt circumferential cross sections of a volute by means of LDV. It is shown that the swirl has a foreced vortex type velocity distribution and that the location of the swirl center changes with mass flow. The throughflow velocity distribution is primarily defined by the conservation of angular momentum. A strong interaction between the throughflow and swirl velocity is observed. Flow visualization in the tongue region reveals a reversal of the velocity at the volute inlet with increasing mass flow

Abstract: Soil structure affects the movement of water in hillslope soils and therefore exerts a strong influence on slope stability. A debris flow is analysed within the confines of an instrumented catchment on the South Island, New Zealand, in order to examine the influence of soil macropores on slope stability. Tensiometric and slope throughflow data for nearby slope areas show that vertical cracks conduct rainfall at rates well in excess of the mineral soil matrix conductivity. The presence of a well connected pipe system at the soil-bedrock interface distributes this water quickly downslope. Under exceptionally high rainfall intensities, however, this crack-pipe system may induce slope instability by increasing the rate of infiltration over lateral pipeflow rates. This results in a build-up of pore pressure at the soilI–rock interface and subsequent slope failure.