Disk Pump Research Articles

Elastic turbulence influences and convective heat transfer within a miniature viscous disk pump

Elastic turbulence is employed within the present investigation to enhance convective heat transfer at very small scales and at very low Reynolds numbers. A miniature viscous disk pump or VDP is utilized to investigate flow and heat transfer, where the latter are based upon energy balance measurements which utilize the mixed-mean temperature at the inlet and outlet of the viscous disk pump passage. The overall heat transfer rate is determined based upon a constant surface temperature thermal boundary condition, and upon a log-mean-temperature difference approach. The VDP operates at rotation speeds of 500RPM, 1000RPM, 1500RPM, 1800RPM, and 2000RPM, which produce overall shear rates across the flow cross section of 146.05 1/s, 292.1 1/s, 438.15 1/s, 525.78 1/s, and 584.2 1/s. A channel depth of 640μm is employed. Elastic turbulence is induced by adding polyacrylamide to water solutions with 65% sucrose by mass. Significant enhancements of mixing and transport are observed, which are associated with the onset and development of elastic turbulence. Such behavior is verified, relative to an increased viscosity Boger fluid, using flow visualization results, rheometer viscosity variations with shear rate, and increases of overall magnitudes of convective heat transfer coefficient, which are augmented by as high as 240%. These comparisons are assessed relative to the Newtonian Boger fluid (which generally does not change viscosity as shear rate varies) at the same rotation speed, shear rate, flow passage height, and inlet temperature. As polymer concentration increases, elastic turbulence effects become more pronounced, and heat transfer coefficient magnitudes increase. This occurs such that Nusselt number ratios are strongly correlated with the mean-square magnitude of scalar temperature fluctuations at the outlet of the VDP. As a result, remarkable heat transfer coefficient enhancements due to elastic turbulence are demonstrated.

Criteria for Small Capacity Pump Type Selection for Two Phase Temperature Control System of Information Support Space Vehicle

The centrifugal pumps are widely used in single-phase temperature control systems of space vehicles. Two phase temperature control system (TPTCS) appear to replace the single phase temperature control systems (SPTCS) at that, hydraulic characteristics of THTCS differ from hydraulic characteristics of SPTCS. This Article gives the grounds for the usage of pump delivery coefficient ns as the pump selection criteria for TPTCS. Based on above mentioned coefficient the comparative analysis of small capacity pumps, namely vortex, disk, and centrifugal being used in aerospace engineering was carried out. The analysis shows the possibility of using the vortex or disk pumps in TPTCS of information support space vehicles. Also, it is suggested to replace the radial flow impeller of these pumps with an axial flow impeller to improve the anti-cavitation characteristics. In this case the pumps will be described as labyrinth pump or labyrinth- screw pumps.

PROSPECTS OF DISK PUMP FOR MECHANICAL CIRCULATORY SUPPORT IN CARDIAC SURGERY (REVIEW)

The need of circulatory support systems in the treatment of chronic heart failure is increasing constantly, as 20% of the patients on the waiting list die every year. Despite the great need for mechanical heart support systems, the use of available systems is limited by its expensiveness. In addition, there is no one system that is 100% responsible to all medical and technical requirements and that would be completely safe for patient. Therefore, further research in the field of circulatory support systems considering health and technical requirements is relevant. One of the new directions in the study are disc pumps of viscous friction for liquid transporting, based on the Tesla pump principle. The operation principle of such pumps is based on the phenomenon of the boundary layer which is formed on the disk rotating in a fluid. There are experimental studies of models with different variants of the rotor suspension, various forms and numbers of the disks, forms of the pump housing. However, none of the above samples was brought to clinical trials. Furthermore, despite the potential of that model there have been no pumps of similar type used so far in circulatory support systems. Published data provide a basis for further development and testing of the pump model and allow hoping for leveling a number of significant shortcomings of modern left ventricular bypass systems.

Miniature Viscous Disk Pump: Performance Variations From Non-Newtonian Elastic Turbulence

Within the present investigation, a miniature viscous disk pump (VDP) is utilized to characterize and quantify non-Newtonian fluid elastic turbulence effects, relative to Newtonian flow behavior. Such deviations from Newtonian behavior are induced by adding polyacrylamide to purified water. The VDP consists of a 10.16 mm diameter disk that rotates above a C-shaped channel with inner and outer radii of 1.19 mm and 2.38 mm, respectively. A channel depth of 230 μm is employed. Fluid inlet and outlet ports are located at the ends of the C-shaped channel. Experimental data are given for rotational speeds of 126 1/s, 188 1/s, 262 1/s, and 366 1/s, pressure rises as high as 700 Pa, and flow rates up to approximately 0.00000005 m3/s. Reynolds number ranges from 2.9 to 6.5 for the non-Newtonian polyacrylamide solution flows and from 51.6 to 149.8 for the Newtonian pure water flows. To characterize deviations due to non-Newtonian elastic turbulence phenomena, two new parameters are introduced, PrR and HCR, where HCR is the ratio of head coefficient (HC) for the polyacrylamide solution and head coefficient for the water solution, and PrR is the ratio of pump power for the polyacrylamide solution and pump power for the water solution. Relative to Newtonian, pure water flows, the polyacrylamide solution flows give pump head coefficient data, dimensional pressure rise data, slip coefficients (SCs), specific speed (SS) values, and dimensional power data, which show significant variations and differences as they vary with flow coefficient (FC) or dimensional volumetric flow rate. Also important are different ranges of specific speed (SS) for the pure water and polyacrylamide solutions, and a lower range of SC or slip coefficient values for the polyacrylamide solution flows, compared to the pure water flows. These variations are due to increased elastic turbulence losses, which occur as viscosity magnitudes increase and the elastic polymers are excited by mechanical stress, which causes them to extend, deform, stretch, and intertwine.

Seal-free design eliminates downtime

Global producer of polymer emulsions and specialty chemicals, Organik Kimya, is able to optimize the safety and reliability of polymer emulsions’ manufacturing at its Rotterdam plant with Mouvex C24i Series Eccentric Disc Pumps.

Enhanced Third Harmonic Generation in Single Germanium Nanodisks Excited at the Anapole Mode.

We present an all-dielectric germanium nanosystem exhibiting a strong third order nonlinear response and efficient third harmonic generation in the optical regime. A thin germanium nanodisk shows a pronounced valley in its scattering cross section at the dark anapole mode, while the electric field energy inside the disk is maximized due to high confinement within the dielectric. We investigate the dependence of the third harmonic signal on disk size and pump wavelength to reveal the nature of the anapole mode. Each germanium nanodisk generates a high effective third order susceptibility of χ((3)) = 4.3 × 10(-9) esu, corresponding to an associated third harmonic conversion efficiency of 0.0001% at an excitation wavelength of 1650 nm, which is 4 orders of magnitude greater than the case of an unstructured germanium reference film. Furthermore, the nonlinear conversion via the anapole mode outperforms that via the radiative dipolar resonances by about 1 order of magnitude, which is consistent with our numerical simulations. These findings open new possibilities for the optimization of upconversion processes on the nanoscale through the appropriate engineering of suitable dielectric materials.

Design of an Improved Turbine Rim-Seal

Rim seals are fitted in gas turbines at the periphery of the wheel-space formed between rotor disks and their adjacent casings. These seals, also called platform overlap seals, reduce the ingress of hot gases which can limit the life of highly stressed components in the engine. This paper describes the development of a new, patented rim-seal concept showing improved performance relative to a reference engine design, using unsteady Reynolds-averaged Navier–Stokes (URANS) computations of a turbine stage at engine conditions. The computational fluid dynamics (CFD) study was limited to a small number of purge-flow rates due to computational time and cost, and the computations were validated experimentally at a lower rotational Reynolds number and in conditions under incompressible flow. The new rim seal features a stator-side angel wing and two buffer cavities between outer and inner seals: the angel-wing promotes a counter-rotating vortex to reduce the effect of the ingress on the stator; the two buffer cavities are shown to attenuate the circumferential pressure asymmetries of the fluid ingested from the mainstream annulus. Rotor disk pumping is exploited to reduce the sealing flow rate required to prevent ingress, with the rotor boundary layer also providing protective cooling. Measurements of gas concentration and swirl ratio, determined from static and total pressure, were used to assess the performance of the new seal concept relative to a benchmark generic seal. The radial variation of concentration through the seal was measured in the experiments and these data captured the improvements due to the intermediate buffer cavities predicted by the CFD. This successful design approach is a potent combination of insight provided by computation, and the flexibility and expedience provided by experiment.

Effect of nanoparticles on the structure and properties of an aluminum alloy poured into a mould with the use of a magnetohydrodynamic disk pump

The influence of two nanomodifiers with different compositions during their homogenization in the AL7 aluminum melt and moulding on the properties of the modified aluminum alloy is studied. Experiments are performed with the use of a centrifugal conductive magnetohydrodynamic pump. The melt is poured into a graphite mould with three cylindrical channels 38 mm in diameter and 160 mm long, which are designed for a metal mass of 500 g. Two compositions are used as modifying agents: nano-scale particles of the aluminum nitride powder 40-100 nm in size and metallized carbon nanotubes smaller than 25 nm, which are clad with aluminum to improve wetting of their surface. The analysis of the structure of the experimental and reference samples shows that the use of modifiers leads to refinement of the grain structure of the cast metal. According to the Hall-Petch theory, this effect may result in improvement of mechanical characteristics of the cast metal.

New standards for the food industry

In Europe, food production has to meet new EC1935/2004 standards. This requires that food processors must ensure their products are not adversely affected by the equipment used to create it. Paul Cardon, industrial products manager, Mouvex, reviews the role of eccentric disc pumps in this effort.

Disc technology continues to spin

Over a century after its invention, Andre Petit's eccentric movement principle has proved to be a reliable solution for the transfer of water and other produced liquids. Today, eccentric disc pumps are a prominent component in product-transfer applications in chemical, energy, sanitary and military sectors.

Deviations Due to Non-Newtonian Influences Within a Miniature Viscous Disk Pump

A miniature viscous disk pump (VDP) is utilized to characterize and quantify non-Newtonian fluid deviations due to non-Newtonian influences relative to Newtonian flow behavior. Such deviations from Newtonian behavior are induced by adding different concentrations of sucrose to purified water, with increasing non-Newtonian characteristics as sucrose concentration increases from 0% (pure water) to 10% by mass. The VDP consists of a 10.16 mm diameter disk that rotates above a C-shaped channel with inner and outer radii of 1.19 mm, and 2.38 mm, respectively, and a channel depth of 200 μm. Fluid inlet and outlet ports are located at the ends of the C-shaped channel. Within the present study, experimental data are given for rotational speeds of 1200–2500 rpm, fluid viscosities of 0.001–0.00134 Pa s, pressure rises of 0–220 Pa, and flow rates up to approximately 0.00000005 m3/s. The theory of Flumerfelt is modified and adapted for application to the present VDP environment. Included is a new development of expressions for dimensionless volumetric flow rate, and normalized local circumferential velocity for Newtonian and non-Newtonian fluid flows. To quantify deviations due to the magnitude non-Newtonian flow influences, a new pressure rise parameter is employed, which represents the dimensional pressure rise change at a particular flow rate and sucrose concentration, as the flow changes from Newtonian to non-Newtonian behavior. For 5% and 10% sucrose solutions at rotational speeds of 1200–2500 rpm, this parameter increases as the disk dimensional rotational speed increases and as the volumetric flow rate decreases. Associated magnitudes of the pressure difference parameter show that the fluid with the larger sucrose concentration (by mass) produces significantly larger differences between Newtonian and non-Newtonian fluid flow, for each value of dimensional volumetric flow rate. For each disc rotational speed, compared to Newtonian data, dimensional pressure rise variations with dimensional volumetric flow rate, which are associated with the non-Newtonian data, are generally lower when compared at a particular volumetric flow rate. Agreement with analytic results, for any given flow rate, rotational speed, and flow passage height, validates the shear stress model employed to represent non-Newtonian behavior, as well as the analytic equations and tools (based upon the Navier–Stokes equations) which are employed to predict measured behavior over the investigated range of experimental conditions.

On dimensionless parameters for generalization pressure head and flow rate characteristics of centrifugal disk pumps

Experimental study was performed for operation of a centrifugal disk pump at atmospheric air pressure. The dimensionless parameters were developed for generalization of experimental data on flow rate and head of the pump. The method for calculation of a pumping curve and throttling characteristic was offered through use of semiemperical generalization formulas. The method ensures a good accuracy in calculations, which is proved by comparison of calculation and experimental data for the pump tested.

The Numerical Simulation of Gas-Liquid-Solid Three-Phase Flow in the Disc Pump

In this paper, the flow law of gas-liquid-solid three-phase flow was studied in the disc pump internal, established a set of numerical simulation method that calculated multiphase flows of disc pump internal. Finally the structure of the disk pump impeller was improved, and designed a new disc pump with multiple-blade structure, through numerical simulation calculation for the gas-liquid-solid three-phase flow of the disc pump internal, mastered change rule of fluid pressure and speed in disk pump internal, obtained relation curves between the different solid phase particle concentration with different gas phase concentration and the head with the efficiency of the pump. The head of the new disc pump was significantly improved by analyzing the disc pump head curve and the actual application.

Reef Climate Adaptation Research and Technology

The authors describe research into technological means for addressing two consequences of climate change for coral ocean acidity and increasing sea surface temperatures leading to coral bleaching. Technology for a multi- integrated response is proposed. Sea surface temperatures can be monitored via satellite and on-line telemetry. Technology for moderating sea surface temperature spikes is based on pumping deeper cool seawater over coral reefs. The technology proposed includes plastic collapsible pipelines that can be deployed like oil spill booms with flat disc pumps and renewable energy devices (tidal turbines) to power the pumps. The technology for counteracting increasing ocean acidity on coral reefs is based on the Accelerated Weathering of Limestone (AWL). It is proposed that an acceleration of the natural process that restores the carbon balance, can be realized using a modified electrolyzer powered by renewable energy. The AWL process sequesters CO₂ and produces H₂ while generating a buffer solution that increases reef pH and also provides alkalinity to feed reef and shellfish calcification. The AWL buffer solution will be distributed where required using the same renewable energy powered pumps and pipelines as used to mitigate sea surface temperature spikes. The AWL process will operate continuously but can be interrupted whenever the pumps and collapsible pipes are required to avoid potential coral thermal bleaching events. Dual use improves affordability.

Slip due to surface roughness for a Newtonian liquid in a viscous microscale disk pump

In the present study, hydrophobic roughness is used to induce near-wall slip in a single rotating-disk micropump operating with Newtonian water. The amount of induced slip is altered by employing different sizes of surface roughness on the rotating disk. The magnitudes of slip length and slip velocities increase as the average size of the surface roughness becomes larger. In the present study, increased slip magnitudes from roughness are then associated with reduced pressure rise through the pump and lower radial-line-averaged shear stress magnitudes (determined within slip planes). Such shear stress and pressure rise variations are similar to those which would be present if the slip is induced by the intermolecular interactions which are associated with near-wall microscale effects. The present slip-roughness effects are quantified experimentally over rotational speeds from 50 to 1200 rpm, pressure increases from 0 to 312 kPa, net flow rates of 0–100 μl/min, and fluid chamber heights from 6.85 to 29.2 μm. Verification is provided by comparisons with analytic results determined from the rotating Couette flow forms of the Navier–Stokes equations, with different disk rotational speeds, disk roughness levels, and fluid chamber heights. These data show that slip length magnitudes show significant dependence on radial-line-averaged shear stress for average disk roughness heights of 404 and 770 nm. These slip length data additionally show a high degree of organization when normalized using by either the average roughness height or the fluid chamber height. For the latter case, such behavior provides evidence that the flow over a significant portion of the passage height is affected by the roughness, and near-wall slip velocities, especially when the average roughness height amounts to 11% of the h=6.86 μm passage height of the channel. Such scaling of the disk slip length bdisk with fluid chamber height h is consistent with d-type roughness scaling in macroscale flows.

원반형 경계층 펌프의 전산 설계

A kind of disk-shape boundary layer pump is designed numerically by using a software of computational fluid dynamics, which is widely used for the special purposes such as artificial hearts, bio-fluidics and transportation of oceanic lives, etc. From the numerical simulation with an axisymmetric model, some benchmark problems are tested and compared with experimental results. The performance of disk pump is graphically visualized from the computational results, and converted to the dimensionless parameters. Finally, the obtained numerical data in the present investigation can be used for the baseline for new design to achieve a more efficient disk pump.

1214 多層円板層流ポンプの性能と内部流れに関する研究(OS12-3 流体機械の諸問題,オーガナイズドセッション)

1214 多層円板層流ポンプの性能と内部流れに関する研究(OS12-3 流体機械の諸問題,オーガナイズドセッション)

An Engineering Model of a Disc Pump Stage for Heavy Oil

AbstractAn engineering model of a laminar flow in a disc pump stage of simple design is developed and an approximate analytical solution for a flow in the disc rotor obtained. A rough analytical model for the vaneless diffuser is also found. The performance of a disc stage as it depends on the fluid viscosity, the flow rate, and a channel number is analyzed.

Blackmer C-Series Eccentric Disc Pumps offer operational and energy-savings advantages in paint and coatings applications

Blackmer C-Series Eccentric Disc Pumps offer operational and energy-savings advantages in paint and coatings applications

Temperature distribution in disk active elements of lasers with longitudinal diode pumping

Experimental and computational data for determination of temperature profile in the region of crystalline laser disk pumping are presented. The analytical relations obtained link the values of temperature, pumping spot radius, and disk thickness and allow optimization of these parameters in the choice of laser construction. Good agreement between computational and experimental results is demonstrated on an example of an Nd:YVO4 crystal disk active element.