Abstract: High sea surface temperatures in the western Pacific warm pool fuel atmospheric convection and influence tropical climate. This region also hosts the Indonesian throughflow, the network of currents through which surface and thermocline waters are transported from the western equatorial Pacific Ocean into the Indian Ocean. Here we show, using records of the delta O-18 and Mg/Ca of planktonic foraminifera from eight sediment cores, that from about 10,000 to 7,000 years ago, sea surface temperatures in the western sector of the western Pacific warm pool were about 0.5 degrees C higher than during pre-industrial times. We also find that about 9,500 years ago, when the South China and Indonesian seas were connected by rising sea level, surface waters in the Makassar Strait became relatively fresher. We suggest that the permanent reduction of surface salinity initiated the enhanced flow at lower, thermocline depths seen in the modern Indonesian throughflow. However, the uniformly warm sea surface temperatures found upstream and downstream of the Indonesian throughflow indicate that the early Holocene warmth in this region was not directly related to reduced heat transport by the throughflow that may have resulted from surface freshening of the Makassar Strait. Instead, we propose that the elevated temperatures were the result of a westward shift or expansion of the boundaries of the western Pacific warm pool.

Abstract: The vertical throughflow with viscous dissipation in a horizontal porous layer is studied. The horizontal plane boundaries are assumed to be isothermal with unequal temperatures and bottom heating. A basic stationary solution of the governing equations with a uniform vertical velocity field (throughflow) is determined. The temperature field in the basic solution depends only on the vertical coordinate. Departures from the linear heat conduction profile are displayed by the temperature distribution due to the forced convection effect and to the viscous dissipation effect. A linear stability analysis of the basic solution is carried out in order to determine the conditions for the onset of convective rolls. The critical values of the wave number and of the Darcy–Rayleigh number are determined numerically by the fourth-order Runge–Kutta method. It is shown that, although generally weak, the effect of viscous dissipation yields an increase of the critical value of the Darcy–Rayleigh number for downward throughflow and a decrease in the case of upward throughflow. Finally, the limiting case of a vanishing boundary temperature difference is discussed.

Abstract: Interocean exchange of thermocline water is of central importance to the mass, heat and freshwater budgets of the major ocean basins. Fluctuations of interocean exchange may be expected to affect the global climate system by altering sea-air heat flux and associated large scale ocean overturning. Interocean exchange of thermocline waters include: Agulhas leakage which injects Indian Ocean water into the Atlantic Ocean; and the transfer of Pacific water into the Indian Ocean by way of the Indonesian Throughflow and along a route south of Australia, the Tassie Leakage. Observations and modeling work of the last few decades have informed us of the nature these key interocean exchanges and offer concepts for costeffective approaches for sustained observing systems.

Abstract: This chapter contains a review of the thermoconvective instabilities that may occur in a fluid saturated porous medium. Reference is made to a horizontal porous layer. The macroscopic description of the fluid flow in a porous medium is outlined. Then, the mass, momentum and energy balance equations for porous media are described and discussed. As a first basic example of convective instabilities, the classical Darcy-Benard problem is studied in order to highlight the main characteristics of the linear stability analysis. Extensions of the Darcy-Benard problem based on the Forchheimer model and on the Brinkman model of momentum flow are analysed. Moreover, the effects of either a horizontal or a vertical throughflow in the layer are discussed. The contribution of the effect of viscous dissipation is investigated as a possible cause of convective instabilities.

Abstract: Changes in the Indonesian Throughflow (ITF) and the South China Sea throughflow—measured by the Luzon Strait Transport (LST)—associated with the 1976/77 regime shift are analyzed using the Island Rule theory and the Simple Ocean Data Assimilation dataset. Results show that LST increased but ITF transport decreased after 1975. Such changes were induced by variations in wind stress associated with the regime shift. The strengthening of the easterly wind anomaly east of the Luzon Strait played an important role in the increase of LST after 1975, while the westerly wind anomaly in the equatorial Pacific contributed significantly to the decrease in ITF transport after 1975, accounting for 53% of the change. After 1975, the Kuroshio Current strengthened and the Mindanao Current weakened in response to a decrease in the total transport of the North Equatorial Current. Both the North Equatorial Countercurrent and the South Equatorial Current weakened after 1975, and an anomalous cyclonic circulation in the western equatorial Pacific prevented the tropical Pacific water from entering the Indian Ocean directly.

Abstract: A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglecting the circumferentially non-uniform and viscous terms. An inviscid blade force model similar to the Large-particle method is derived. The viscous blade force has been modeled by the distributed loss model. The convective fluxes of the governing equation are discretized with the Edward’s low-diffusion flux-splitting (LDFSS) scheme. And a point-iterative Symmetric Gauss-Seidel (SGS) scheme is used in the temporal discretization. The throughflow model has been applied to the NASA Rotor 67 and a high-load transonic fan stage ATS-2. The reasonable good agreements with the experiments and the 3D viscous computations show the potential of the method.

Abstract: This paper discusses experimental results from a two cavity test rig representative for the internal air system of a high pressure compressor. Thermal steady state measurements of the time-averaged local heat fluxes on both sides of the mid disc are presented for three different flow regimes: pure axial throughflow of cooling air and axial throughflow of cooling air in two directions with a superposed radial inflow of hot air in one cavity. Mass flow ratios between 1/40 < mrad /max < 2/1 are measured. Tests were carried out for a wide range of non-dimensional parameters: Re φ up to 107 , Rez up to 2 × 105 and Cw up to −2.5 × 104 . In all cases the shroud is uniformly heated to approximately 100°C. The local axial heat fluxes are determined separately for both sides of the mid disc from measurements of the surface temperatures with open spot-welded thermocouples. The method of heat flux determination and an analysis approach calculating the uncertainties and the sensitivity are described and discussed. The local heat flux results of the different flow paths are compared and interpreted by assumed flow structures. The time-averaged heat flux results can adequately be interpreted by flow structures of two toroidal vortices for axial throughflow and a source-sink flow for the radial inflow. The measurements show that the axial heat flux can change the direction, i.e. areas exist where the disc is heated and not cooled by the flow. For axial throughflow a local minimum of heat flux exists on the impinged side in the range of x = 0.65 if the axial Reynolds number is low or the rotational Reynolds number is high. On the back side a heating area exists in all tests in the lower half of the disc (x < 0.6) due to recirculated air of higher temperature. This heating area corresponds to the range of the inner vortex and increases with higher axial and rotational Reynolds numbers.Copyright © 2010 by ASME

Abstract: A surface pathway of the subsurface Indonesian Throughflow (ITF) in the southeastern Indian Ocean is proposed using a combined analysis of Lagrangian particles and passive tracers derived from two independent tools: an Ocean General Circulation Model (OGCM) and Simple Ocean Data Assimilation (SODA.2.0.2) reanalysis data. This newly suggested pathway follows the processes in succession as upwelling in the south Java coast, offshore Ekman drift and subduction into the thermocline centered on 20∘S. The upwelling of subsurface ITF along the south Java coast is found to occur from August to October. Upon surfacing, the ITF advects southwestward being trapped in the surface Ekman layer for an approximate period of 260 days and reaches the southeastern tropical Indian Ocean subduction zone centered on 20∘S which is demarcated by the Zero Wind Stress Curl (ZWSC) and subducts there. The particle trajectory revealed that during the subduction within the ZWSC region, the surface eastward flow above 120 m depth carries the particle about 10∘ to the east and westward flow below this depth carries the particle to the western Indian Ocean along the thermocline. These pathways are confirmed by a series of tracer experiments using SODA reanalysis data. The effects of vertical mixing and entrainment on the surfacing of the ITF at south Java coast were identified.

Abstract: A closable throughflow member comprises a housing (1, 101) which defines a flow path for moisture and/or liquid through the housing. A check valve (17, 117) is provided within the housing and is adapted to close in the event of substantial liquid flow in one direction.

Abstract: Radial and mixed flow turbines are important components of turbochargers in automotive engines. Their aerodynamic design is generally compromised by severe mechanical constraints, to deal with high temperature and unsteady operation, but also by the requirement of low inertia for rapid turbocharger response from low engine speed. Conventionally, the designer deals with these constraints in the preliminary design, using a high degree of empiricism, followed by extensive CFD analysis and geometry optimisation. This paper describes a new approach to the preliminary design using a quasi-3D throughflow method coupled to an optimiser, which allows a more rapid consideration of the design issues before moving on to 3D CFD analysis. The throughflow-based optimisation system was able to increase efficiency by over 3% at the same inertia or to reduce inertia by 20-30% at the same efficiency, compared to a baseline design.

Abstract: A supply air terminal device (1) with a main chamber (2) configured to have air (3) flowing through it. The main chamber (2) comprises an inlet (4) for inflow of air (3) from a source disposed outside the supply air terminal device (1), and a bottom plate (5), which bottom plate (5) comprises air flow passages (7a, 7b) running through it for throughflow of at least part of the air (3) from an inside to an outside of the main chamber (2). An adjustable regulating element (10) is disposed in the supply air terminal device (1). The regulating element (10) comprises inside the main chamber (2) and at a distance from the airflow passages (7a, 7b) at least one beam element (12a, 12c). The beam element (12a, 12c) is connected to means (13a, 13b, 13c) with a respective direction from the beam element (12a, 12c) towards and through a respective airflow passage (7a, 7b). Each means (13a, 13b, 13c) has in its direction per unit length a narrowing cross-sectional area and is adjustable in the respective air flow passage (7a, 7b) so that a throughflow cross-section for the respective air flow passage (7a, 7b) can be adjusted between at least a first size of throughflow cross-section and at least a second size of throughflow cross-section.

Abstract: The computation time and the extraction of useful information remain severe drawbacks to systematic use of modern three-dimensional Navier-Stokes codes in a design procedure of multi-stage turbomachines. That explains why throughflow simulation is still widely used at industrial scale. The main limitation of throughflow is however the need for empirical models to reproduce blade-flow interactions and major 3D flow features. The purpose of this work is to investigate the degree to which empiricism could be reduced by using the averaged-passage equations of Adamczyk, combined with a harmonic closure strategy. To that aim, results of a computation performed with a steady three-dimensional Navier-Stokes code are used to calculate some of the additional terms of the circumferentially-averaged equations, the so-called circumferential stresses. The importance of the latter to bring back the mean effect of circumferential non-uniformities, linked to 3D phenomena, is illustrated by injecting them into a throughfow simulation. Then the ability of truncated Fourier series to reproduce the level of non-uniformity in the core flow and near the walls is detailed. It is finally shown that the harmonic approximated stresses can lead to a good reproduction of local 3D flow features in throughflow simulation and to a better accuracy.Copyright © 2010 by ASME

Abstract: Capturing a level of modeling of the flow inside a multistage turbomachine, such as unsteadiness for example, can be done at different levels of detail, either by capturing all deterministic features of the flow with a pure unsteady method or by settling for an approximated solution at a lower computational cost. The harmonic methods stand in this second category. Among them, the “nonlinear harmonic method” (NLHM) from He and Ning [1998, “Efficient Approach for Analysis of Unsteady Viscous Flows in Turbomachines,” AIAA J., 36, pp. 2005–2012] revealed the most efficient. This method consists of solving the fully nonlinear 3D steady problem and a linearized perturbation system in the frequency domain. As it has been shown by the authors that the circumferential variations exhibit a harmonic behavior, it is proposed here to adapt the NLHM to the throughflow model, where the main nonlinear system would be the common throughflow equations and the auxiliary system would give access to the circumferential stresses. As the numerical local explicit impermeability conditions are unsupported by Fourier series, the adaptation of this technique to the throughflow model relies on a reformulation of the blade effect by a smooth force field as in the “immersed boundary method” from Peskin [2002, “The Immersed Boundary Method,” Acta Numerica, 11, pp. 1–39]. A simple example of an inviscid flow around a cylinder will illustrate the preceding developments, bringing back the mean effect of the circumferential nonuniformities into the meridional flow.

Abstract: A numerical study has been carried out to study fluid flow within a rotor-stator system with an inward throughflow and pre-rotation. Furthermore, the effect of flow parameters on the flow structure has been investigated. The entrainment coefficient, beta, of the rotating fluid and the rotating disc moment coefficient have been calculated. A correlation has been found for predicting the place of stagnation point. The results show the Batchelor type of flow with two separated boundary layers on the rotating and stationary discs. The numerical results are compared with the available measured data and generally, a good agreement has been encountered.

Abstract: In this thesis,the cooling air network system of a gas turbine is studiedBased on the analyses of cooling methods,cooling configuration and flow path configuration,the cooling air network system is simulated as a complicated network system which is composed of different throughflow elements connected in series or in parallelThe relations for determine the pressure loss and heat transfer rate of air flow in each throughflow elements are given by using available empirical relations,and equations of flow,pressure and temperature which describe the fluid dynamic characteristics and heat transfer characteristics are presentedTo solve governing equations the flow distribution of cooling air is achieved by simplifying the cooling air network system step by step,while a stable solution method for large sparse matrix linear equations based on the GAUSS ELIMINATION is used to solve the pressure and temperature distribution of cooling airBy using the developed program the fluid dynamic characteristics and heat transfer characteristics of turbine cooling air network system are calculated and analyzed,and the key parameters of the system such as distribution of air pressure,temperature and flow,etc

Abstract: A reliable design of modern, multi-stage axial compressors requires an accurate and detailed description of the flow field in order to ensure an optimal adjust ment of the stages. Therefore a throughflow procedure for multi-stage axial compressors on the basis of pitch averaged RANS equations is presented. Effects of the blading on the flow suc h like deflection, losses and mixing processes are represented by blade forces and loss correlations. Endwall boundary layers are accounted for by solving the viscous momentum equations. The averaged equations include additional terms, which also have to be modeled for closure reasons. The integration over the time scale of turbulent motion leads to the Reynold stresses. They are described by a turbulence model, which is based on the eddy viscosity concept and includes an algebraic approach on the basis of a mixing length. The integration in circumferential direction leads to further correlation terms, so-called deterministic stresses, which reflect the influen ce of the three-dimensionality. The significance and the influence of these additional terms on the meri dional flow are studied within the present investigation.

Abstract: The ball valve has a filter element (3) attached inside a throughflow opening of the ball cock plug (4) The method is implemented for half or complete automatic cleaning of the filter element by a clean blowing of a compressed-air or by cleaning the medium over a nozzle in the interior of throughflow opening of the ball cock plug (2) and by the discharge units (13,15) The impurities flung towards exterior of the throughflow opening of the ball cock plug are either evacuated or permeated

Abstract: In order to study flow mechanism in disc pump,the CFD technology was applied to simulate the 3D flow in the model pump to acquire the distribution of absolute velocity and static pressure in bladeless zone and blade zone of impeller.Velocity vectors,velocity contours and pressure contours was analyzed.Rotational flow is considered as the main flow in the impeller.Good ability to throughflow in disc pump is attributed to low pressure in most of bladeless zone in impeller,run-through flow in in bladeless zone and blade zone of impeller,and run-through flow transfer angular momentumto flow in bladeless zone.

Abstract: The method involves recording of signals that are produced by turbulence of fluid (F), and evaluating the recorded signals. Vibration and/or oscillation of a wall (3) that partially surrounds the fluid are recorded as the signals. The recorded signals are amplified before the evaluation. The turbulence is caused by passage of the fluid via a passage opening (5). The vibration and/or oscillation of the wall are detected by using piezo electrical sensors (6), which are arranged at the wall outside a flow channel (2). An independent claim is also included for a device for measuring flow rate of fluid in the flow channel.

Abstract: A method for regulating metal melt throughflow through a melt throughflow aperture in a bottom nozzle of a metallurgical vessel is provided. The bottom nozzle has an upper nozzle arranged in a floor of the metallurgical vessel and a lower nozzle arranged below the upper nozzle. The method includes introducing inert gas through at least one inert gas inlet aperture into the melt throughflow aperture in the bottom nozzle, arranging a temperature sensor on or in the lower nozzle for determining a temperature in a wall of the bottom nozzle, and regulating an inert gas supply into the bottom nozzle using measurement signals from the sensor. A decrease in the temperature signals an increase of metal clogging and an increase in the temperature signals a decrease of metal clogging.

Abstract: The effects of vertical through flow, variable density and temperature dependent viscosity on the onset of convection in a Newtonian fluid-saturated porous layer are studied. The Darcy-Forchheimer equation is used to describe the flow in a porous medium. The resulting eigenvalue problem is solved using momentum method combined with the Galerkin technique. It is found that the strength and direction of through flow, density variable coefficient η, viscosity parameter Γ and inertia parameter G significantly influence the critical Rayleigh number. The principle of exchange of stability is valid in this case. In contrast to the results of homogeneous flow, the direction of through flow alters the stability of the system even if the boundaries are of same type. The Rayleigh number R is computed numerically for different values of density variable coefficient η, viscosity parameter Γ and inertia parameter G. The results reveal that increase in the value of η is to hasten the onset of convection while increase in the value of Γ and G is to delay the onset of convection.

Abstract: The water masses in both routes of Indonesia Throughflow (ITF) from historical hydrographic data are examined by means of the Principal Component Analysis (PCA), a multivariate statistical technique, during the southeast monsoon and northwest monsoon, and compared with the TS diagrams. The temperature and dissolves oxygen always play in the same PC, which describeds a variability contribution of the water mass characters, while salinity in a different PC. The relationship of the water masses parameters may indicate the character of dissolved oxygen as a non-conservation tracer. The Principle Component Analysis may also be used to follow the trendds of core layer attenuation as verified by the salinity corresponds at the PC. It will be higher with S-max and S-min and more closely resemble the sources. This condition is shown in the waters close to the main sources in the Pacific, like Sulawesi, Malkuku and Halmahera Sea, where both the salinity extrema can still be observed. Conversely, in the Banda and Timor Sea, where S-max and S-min are greatly attenuated even completely remove, the correspondence of salinity in the water mass character variability becomes smaller. As seen on TS and TO diagrams, PCA graphics are also showed the dominant of the north Pacific water in the western route seas, the Sulawesi, Makasar Strait and the Florest Sea, but relatively salty water of South Pacific origin is observed in the Halmahera Sea, particularly in the northwest monsoon. The strong seasonal variablity of surface water in the Indonesian can also be observed in the PCA graphics. Keywords: Water Mass, Indonesian Throughflow, PCA.