Pumping Conditions Research Articles

Impacts of Fracture Roughness and Near-Wellbore Tortuosity on Proppant Transport within Hydraulic Fractures

For unconventional reservoir hydraulic fracturing design, a greater fracture length is a prime factor to optimize. However, the core observation results from the Hydraulic Fracturing Test Site (HFTS) show that the propped fractures are far less or shorter than expected, which suggests that the roughness and tortuosity of hydraulic fractures are crucial to sand transport. In this study, a transport model of sands is first built based on experimental measurements on the height and transport velocity of the sand bank in fractures with predetermined width and roughness. The fracture roughness is quantified by using the surface height integral. Then, three-dimensional simulations are conducted with this modified model to further investigate the impact of tortuous fractures on sand transport, from which a regression model is established to estimate the propped length of hydraulic fractures at a certain pumping condition. The experiment results show that the height of the sand bank in rough fractures is 20–50% higher than that in smooth fractures. The height of the sand bank decreases with the reduction in slurry velocity and increases with the increase in sand diameter. Sand sizes do little effect on the transport velocity of the sand bank, but the increase in slurry velocity and sand volume fraction can dramatically enhance the migration velocity of the sand bank. The appearance of tortuous fractures decreases the horizontal velocity of suspended particles and results in a higher sand bank compared with that in straight fractures. When the sand bank reaches equilibrium at the tortuous position, it is easy to produce vortices. So, there is a significant height of sand bank change at the tortuous position. Moreover, sand plugging can occur at the entrance of the fractures, making it difficult for the sand to transport deep into fractures. This study explains why the propped length of fractures in HFTS is short and provides a regression model that can be easily embedded in the fracturing simulation to quickly calculate dimensions of the propped fractures network to predict the length and height of propped fractures during fracturing.

Influence of Inlet Groove on Flow Characteristics in Stall Condition of Full-Tubular Pump

The full-tubular pump is a new type of pump with a narrow range of stable operation. In order to improve the internal flow characteristics of the full-tubular pump under small flow conditions and improve the safe and stable operating range of the pump, this paper conducts numerical simulation of the full-tubular pump model based on the Reynolds time-averaged N-S equation and the SST k-ω turbulence model. The improvement mechanism of the parameters of the inlet grooves on the stall area of the full-tubular pump is studied, and the reliability of the numerical simulation of the full-tubular pump is verified by model tests. The research results show that the inlet groove can improve the head and efficiency of the full-tubular pump in the small flow area, and the head at the deep stall condition is increased by nearly 1.61 m. The inlet groove increases the pressure difference of the impeller, which increases the head and improves the hump. At the same time, the increase in the pressure difference of the impeller increases the backflow flow in the gap between the stator and the rotor. The groove can reduce the vortex strength and backflow range at the inlet pipe wall near the stall operating, and also improve the flow field at the impeller inlet. In terms of pressure pulsation, the groove can effectively suppress the low-frequency pressure pulsation at the inlet of the impeller of the full-tubular pump under stall conditions, and effectively reduce the amplitude of the main frequency pressure pulsation and improve the internal flow. The research in this paper can provide a reference for improving the flow characteristics in the stall condition of the full-tubular pump.

Thermal-hydraulic performance of additively manufactured lattices for gas turbine blade trailing edge cooling

• Thermal-hydraulic performance of four lattice frame materials, namely, Octet, Tetrakaidecahedron, Face diagonal-cube, and Cube is studied for turbine edge cooling application. • Face diagonal-cube provided the highest heat transfer coefficient and pressure drop values amongst the investigated samples at similar porosity values and unit cell size. • Cube topology yielded the lowest flow losses and consequently highest thermal–hydraulic performance of ∼ 2.78 at the lowest investigated Reynolds number. Gas turbine blade trailing edge cooling is challenging because of the stringent geometrical constraints driven by aerodynamics and thermal stresses. The blade topology becomes significantly thin towards the trailing edge which leaves a narrow room for the construction of internal cooling channels and also makes this section susceptible to failure due to thermal stresses. Conventionally, pin-fins are employed in the internal cooling channels of the trailing edge because they provide high levels of heat transfer coefficient values and also structural integrity. Much of the past studies on pin fins have focused on their relative arrangements, heights, crossflow scheme, etc., with an aim to enhance the endwall heat transfer coefficient as well as leverage the conjugate heat dissipation capabilities of these “extended surfaces”. Lattices on the other hand, have been investigated to a lesser degree, and some studies can be found for blade mid-chord region, however, with their manufacturability challenges at that time, the concepts did not gain traction. Lattices are far more complex topologies with superior local heat transfer characteristics as well as high conjugate heat dissipation capabilities due to large wetted surface area. With the recent advancements in metal additive manufacturing, complex topologies such as lattices can be revisited due to high chances of their realization now. To this end, we are presenting our study on lattices additively manufactured in 420 Stainless Steel (thermal conductivity nearly twice of Inconel 718), where four different unit cell topologies, (a) Octet, (b) Tetrakaidecahedron, (c) Face diagonal-cube, and (d) Cube, were printed using Binder Jetting technology. The aim of this study is to characterize the conjugate heat transfer capabilities of these lattices manufactured in 420 Stainless Steel prior to conduct similar study with Inconel 718, due to relatively simpler additive manufacturing route of Binder jetting (420 stainless steel) compared to Direct Metal Laser Sintering (Inconel 718). The intended design porosity of the samples was 0.886 and the coupons had single unit cell (edge size of 10 mm) in the thickness. The steady-state experiments were conducted to evaluate the effective thermal conductivity and forced convective heat transfer performance. For forced convection, the experiments were conducted for a wide range of Reynolds numbers with air as the working fluid. Overall heat transfer coefficient, pressure drop, Nusselt number and friction factor enhancement level and pumping power requirements of these structures are presented. The implications of the porosity variation due to manufacturing process on the interpretation of relative performance trends is discussed. The effective thermal conductivity was independent of the topology for considered porosity value. Face diagonal-cube yielded the highest heat transfer and pressure drop for the investigated Reynolds number range. However, Cube provided the best overall thermal hydraulic performance value of 1.94 to 2.78 for the investigated range of Reynolds number. At fixed pumping power conditions, Cube was capable of providing the highest heat transfer coefficient.

1.7 <bold>μ</bold>m self-synchronized picosecond pulsed random Raman fiber laser

Aiming at the structural complexity of the current 1.7 μm band short pulse lasers, we propose and implement a self-synchronized picosecond pulsed random Raman fiber laser. The half-open Raman cavity based on random distributed feedback is pumped by a 1 578 nm pulsed fiber laser to achieve a picosecond pulse output with a central wavelength of 1 695 nm and an average power of 224 mW. The composite cavity formed by distributed Rayleigh scattering automatically satisfies the synchronous pumping condition without the need for precise matching of cavity length or complex feedback control in the system. By inserting a wavelength division multiplexer in the cavity, the random sub-cavity noise is suppressed and the stability of the output pulse is improved. To the best of our knowledge, this is the first realization of a random pulse fiber laser operating at 1.7 μm, which can be widely used in bioimaging and material processing. <fig fig-type="abstract-image" id="F1" orientation="portrait" position="float"><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="1000-2618-2022-39-4-363/7A9ED982-4F80-49df-B290-3AA8759A767B-F001.jpg"/></fig>

Optimization of pumping conditions in end pumped Tm: YAP lasers with the consideration of thermal effects

Optimization of pumping conditions in end pumped Tm: YAP lasers with the consideration of thermal effects

Optimization of the Radiation Response of Backup Optical Fiber Amplifiers for Space Missions

We investigated the X-ray radiation impact on the performances of “backup” erbium-doped fiber amplifiers (EDFAs) and erbium-ytterbium-doped fiber amplifier (EYDFA). These devices are exposed to the space radiation constraints, unpowered in the “OFF” mode, up to their hypothetic activation during the mission. This atypical profile of use must be considered as it could lead to a higher radiation vulnerability. To carry out this study, active optical fibers differing in terms of radiation hardness have been exposed to steady-state X-rays under different profiles of amplifier use: the gain degradation is measured by varying the pumping conditions, that drive the photobleaching (PB) phenomenon, during the radiation exposure: “ON” (100% ON), “OFF” (0% ON), and “OFF–ON–OFF” with powering 2% or 10% of the time. Our results show that the impact of the pump and its related PB efficiency depend on the selected active fiber to build the amplifier. An important result is that the “backup” EDFA designed with radiation-hardened Ce-doped fiber does not suffer from an extra-degradation due to the “OFF” mode, contrary to the one designed with a nonrad-hard fiber. For this latter one, it is indeed possible to reduce the extra-gain degradation by powering the amplifier for short time periods during the “OFF” state; otherwise, the EDFA recovers this extra-gain degradation in a few hours after turning “ON” in our test conditions. For the tested radiation-tolerant EYDFA, an enhanced vulnerability is observed for the “OFF” amplifier, that can be reduced too by briefly powering the amplifier. The origins of these effects are discussed based on the properties of point defects related to the aluminosilicate (EDFA) and phosphosilicate (EYDFA) glasses of the fiber.

Predictive Maintenance Model Based on Multisensor Data Fusion of Hybrid Fuzzy Rough Set Theory Feature Selection and Stacked Ensemble for Fault Classification

With the rising demand for integrated and autonomous systems in the field of engineering, efficient frameworks for instant detection of performance anomalies are imperative for improved productivity and cost-effectiveness. This study proposes a systematic predictive maintenance framework based on the hybrid multisensor fusion technique of fuzzy rough set feature selection and stacked ensemble for the efficient classification of fault conditions characterised by uncertainties. First, a feature vector of time-domain features was extracted from 17 multiple sensor signals. Then, a comparative study of six different Fuzzy Rough Set Feature Selection (FRFS) methods was employed to select the various combinations of optimal feature subsets for various faults classification tasks. The determined optimal feature subsets then served as inputs for training the stacked ensemble (ESB(STK)). In the ESB(STK), Support Vector Machine (SVM), Multilayer Perceptron (MLP), k -Nearest Neighbour ( k -NN), C4.5 Decision Tree (C4.5 DT), Logistic Regression (LR), and Linear Discriminant Analysis (LDA) served as the base classifiers while the LR was selected to be the metaclassifier. The proposed hybrid framework (FRFS-ESB(STK)) improved the classification accuracy with the selected combinations of optimal feature subset size whiles reducing the computational cost, overfitting, training runtime, and uncertainty in modelling. Overall analyses showed that the FRFS-ESB(STK) proved to be generalisable and versatile in the classification of all conditions of four monitored hydraulic components (i.e., cooler, valve, accumulator, and internal pump leakage) when compared with the six base classifiers (standalone) and three existing ensemble classifiers (Stochastic Gradient Boosting (SGB), Ada Boost (ADB), and Bagging (BAG)). The proposed FRFS-ESB(STK) showed an average improvement of 11.28% and 0.88% test accuracies when classifying accumulator and pump conditions, respectively, whiles 100% classification rates were obtained for both cooler and valve.

Online Flow Estimation for Condition Monitoring of Pumps in Aircraft Hydraulics

Hydraulic systems in conventional civil aviation are currently monitored in a very rudimentary way. Normally, measured values are compared with a fixed threshold. If these measured values are outside the predefined limits, the entire hydraulic system is usually shut down. To overcome this deficit, a study regarding a novel prognostic health management method for aircraft hydraulic pumps, which allows a statement about the pump condition, is presented in this paper. The method is based on measuring differential pressure and temperature at a suitable resistance. In the first part of the study, the overall concept for monitoring the motor pump unit is analyzed. This is followed by a discussion of possible measurement methods and suitable resistors to determine the condition of the pump. In the second part of the study, the implementation for online monitoring of the pump is discussed. After a suitable approximation is found, the quality of the proposed method is evaluated with real hydraulic power generation and consumers.

Analysis of Surface Pressure Pulsation Characteristics of Centrifugal Pump Magnetic Liquid Sealing Film

In order to discuss the surface pressure pulsation characteristics of the magnetic-fluid sealing membrane of centrifugal pump, this paper studies the surface pressure pulsation characteristics of the shaft end sealing membrane under different flow operating conditions of centrifugal pump based on the combination of numerical calculation and experimental verification. The results show that the pressure value on the surface of the magnetic-fluid sealing film decreases with the increase of the flow rate of the centrifugal pump, and the pressure on the surface of the magnetic-fluid sealing film has periodic pulsation, and the period is the time required for a single blade to sweep the volute separating tongue. In one rotation cycle of the runner, the number of reciprocating movements of the magnetic-hydraulic sealing film is the same as the number of blades of the runner. The main reason for the pressure pulsation is that the impeller periodically sweeps the fixed surface of the centrifugal pump.

Inter-stage energy characteristics of electrical submersible pump under gassy conditions

Owing to the complex operational conditions of deep-sea or underground, the energy and flow characteristics in the electrical submersible pump (ESP) conditions are even more chaotic under gas-liquid flow, which degrades the energy conversion efficiency. At present, few studies have been carried out to demonstrate the difference between stages of ESP under gassy conditions. In this study, based on the Eulerian–Eulerian inhomogeneous model, an ESP with three stages was simulated to investigate the inter-stage differences in energy characteristics and flow patterns under both pure water and gas-liquid two-phase flow in detail. The simulation results are in good agreement with the experimental data. Gas phase distribution, external and internal characteristics in the ESP with three stages were analyzed at different flow rate with inlet gas volume fraction (IGVF) of 5%, 10%, and 15%. With the rise of IGVF, the degree of gas aggregation in the impellers and diffusers increases significantly, and the influence of the vortex formed by the gas concentration expands, and the differences vanish in gas distribution and flow trajectory between different flow channels. The proportion of gas in the flow channel is negatively correlated with the flow rate. Meanwhile, the variation law of head and efficiency under different inlet gas content conditions is fitted to the equation. The gas distribution pattern became further chaotic as the number of stages increases. The turbulence kinetic energy in the impeller is highly consistent with the gas aggregation pattern in terms of position distribution and change trend. At designed and best efficiency flowrate, the volume average of turbulence kinetic energy inside the second and third impeller is significantly higher than the first impeller. Overall, this study comprehensively reveals the gas phase distribution pattern, energy and internal flow characteristics in the ESP, which is helpful for the optimization design of such a pump and the improvement of the energy conversion efficiency under gassy condition.

Hydrodynamic Simulation of the Influence of Injection Flowrate Regulation on In-Situ Leaching Range

Reasonable control of the leaching range is one of the critical indicators of the in-situ leaching uranium mining process. However, there is currently no mature control technology. To verify and improve the current control technology of the leaching range in the industry, this work proposes an injection control mode for a small flow around the well-site and establishes a hydrodynamic model of the leaching range under eight different pumping and injection conditions by using the groundwater modeling system (GMS). The model calculation, range prediction, comparative analysis, and on-site SO42− and S isotope verification tests were carried out. Results show that with the change of liquid injection ratio, the area ratios of fixed pumping injection ratio (total pumping flowrate is greater than 0.3% of the total injection flowrate) and model leaching range under four pumping injection equilibrium conditions were 99.10%, 99.99%, 98.30%, and 97.95%, respectively. The farthest migration distance ratios of the leaching solution were 99.37%, 100%, 98.02%, and 97.58%, respectively. It is considered that the operation mode with a fixed pumping injection ratio has no noticeable control effect on the leaching range; selecting a reasonable proportion to regulate the flowrate of injection wells at different positions can effectively reduce the area of the groundwater flow field and realize the effective control of the leaching range. The research results are conducive to saving a lot of evaporation pool construction, land acquisition, human and material resource investment, and environmental policy pressure.

Orbital angular momentum supercontinuum generation from near-ultraviolet to infrared in a photonic crystal fiber

We report the numerical analysis of an MgF2 photonic crystal fiber (PCF) for ultraviolet (UV) supercontinuum (SC) generation of vortices. By pumping with 12.8 nJ energy in the anomalous dispersion region to the right of the zero-dispersion wavelength (ZDW) at the blue side, SC spectrum extending from 315 to 3064 nm at −40 dB is formed, and a strong peak at UV band is caused by dispersive wave (DW) generation. Through reasonably setting the pump conditions and fiber length, the energy proportion of < 400 nm reaches 0.36, which exhibits a high UV energy conversion efficiency.

Numerical simulation and sensitivity analysis of automatic optimization of gas extraction well locations in abandoned mines

There are large numbers of abandoned mines in China and abroad, among of which stores relative abundant coal-bed gas. The gas extraction from abandoned mines can be used for power generation or industrial gas utilization. In this paper, the present situation of abandoned mines in China and abroad was studied, and the disadvantages of the common layout and optimization methods of gas extraction in abandoned mines were pointed out. Based on the analysing of reservoir conditions and physical property parameters, the finite element software COMSOL was used to do the numerical simulation of extraction well automatically optimize, and take shenbei coal mine as an example. Moreover, an automatic optimization APP of well location was developed based on the results of simulation. Finally, the parameter sensitivity of gas extraction is analysed. Through the study, it is found that the most basic and common method of gas extraction in abandoned mines is empirical method, which lacks of theoretic support and accuracy, thus causing unreasonable extraction and waste of resources. In this study, the COMSOL numerical simulation software was used to explore the numerical simulation method of automatic well position optimization combined with the optimization algorithm. The Nelder-Mead algorithm was selected as the optimization algorithm after comparing the advantages and disadvantages of various algorithms. The operation flow and type of Nelder-Mead algorithm were analysed, and the optimization parameters of numerical simulation were set. Through the numerical simulation, the function of automatically searching the high-gas production position near the preset well position was realized, and the automatic optimization APP for gas extraction in abandoned mines was developed. Finally, the sensitivity of parameters to gas production in different well locations under three different pumping conditions which are horizontal, vertical and bottom-hole negative pressure was analysed; and the simulation results were discussed.

Quantifying the impacts of groundwater abstraction on Ganges river water infiltration into shallow aquifers under the rapidly developing city of Patna, India

Study regionPatna is located on the southern bank of the River Ganges in Bihar, India. Rapid population growth over the past few decades has driven an increase in groundwater abstraction from aquifers under the city. Study focusThis study exeplores the pumping-induced water exchange between the River Ganges and groundwater under transient conditions between 2009 and 2015, using a numerical simulation. The deterministic water exchange model within an uncertainty quantification was used to reveal the controlling factors affecting river water infiltration. New hydrological insights for the regionModelling reveals that under baseline (eno pumping) conditions, the dominant (~ 91% of the year) flow direction is from the aquifer to the river, which reverses (~ 9% of the year) when the river stage is high. When a municipal pumping well is implemented, river water infiltration into the aquifer increases to 68% of the year. The groundwater pumping rate is found to be the most important factor affecting the river water infiltration, whilst the groundwater table level is most sensitive to the well distance from the river, followed by pumping rate. Optimizing the location, depth and pumping rate of new wells in the area could mitigate fluvial contamination of the aquifer and help maintain groundwater levels.

Model Based Design, Prototyping and Testing of a Small Size High Speed Electrically Driven Centrifugal Pump

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Within automotive sector, there are several high-performance applications, like, for instance, those referred to racing and motorsport, where cooling needs are usually fulfilled by simple circuits with conventional low-efficiency pumps. The cooling needs in these applications are represented by low flow rates delivered (in the range of 10 - 50 L/min). The operating conditions of these small pumps are usually characterized by very high revolution speeds, which intrinsically cause low efficiency and critical intake phenomena (cavitation) if the design is not specifically optimized to address these concerns.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Hence, in this paper a small-size pump operating in the racing sector has been designed using a model-based approach, built and tested having reached both high efficiency (aimed to 50%) and absence of intake operational problems (cavitation). Starting from the specific cooling request (design flow rate equal to 14.0 L/min and pressure rise equal to 2.5 bar), the very limited space available on board oriented the design to an operational revolution speed of 12000 RPM. The interest of this study was to introduce a so high revolution speed in more conventional automotive cooling pumps electrically assisted, keeping high efficiency. In fact, the strong reduction of the size of the pump allows an easy and correct positioning on board.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;The model-based design was done by a two-steps procedure. The first made use of a 0D model which, catching main physical phenomena of the flow even in simplified form, leads to an optimum geometrical design for the impeller and the volute. A final refinement has been done with a CFD code predicting the off-design performance and limiting cavitation zones. Cavitation, which is one of the most critical issues of high-speed pumps, was completely investigated through a CFD numerical analysis.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;The pump has been prototyped and tested on a dynamic test bench for pumps, which reproduces homologation cycles and real driving. A good agreement has been reached between theoretical and experimental results, being the mean relative error on pressure rise for all operating point close to 4 %. This model-based procedure opens the way to support the development of electric water pumps for more conventional applications (automotive, light duty engines) in which a redesign will be focused to manage the thermal state of the engine and reduce the energy absorbed during the homologation cycle.&lt;/div&gt;&lt;/div&gt;

General model of counterpropagating continuous-variable entangled states in lossy waveguides

We present a general theoretical approach to model an integrated source of counterpropagating continuous-variable entangled states in lossy waveguides pumped by a classical pulsed source incident from above the waveguide. We use a backward Heisenberg approach to model the generation of the entangled state and then solve the adjoint master equation to model the propagation of the state in the lossy waveguide. We employ a numerical method to implement the Schmidt decomposition method for the biphoton wave function rather than pursuing analytical methods. This approach allows us to model a wide variety of waveguide systems and pump configurations. We apply our model to the nonlinear generation and propagation of continuous-variable entangled states in a coupled resonator optical waveguide under a variety of different pump conditions and derive the optimal pumping conditions for our system.

Experimental investigation on effect of accelerated speed and rotor material on life of implantable micro-infusion pump tubing

Peristaltic pumps have been put to use in various biomedical applications like devices for the transfer of body fluids as well as devices for controlled release of medication, including implantable infusion pumps. Out of the various components of a peristaltic pump, tubing is considered the most vulnerable part. This study focuses on the performance of Silicone micro-pump tubing used in such an implantable drug delivery device. Long-term implantable medical devices are expected to be operational for about 10 years. But experimental testing of the reliability of components under normal working speeds are time-consuming and thus delays the product development cycle. While simulating the conditions in the laboratory under accelerated speeds, the effect of increasing the speed must be accounted. In this study, the effect of accelerated speed and rotor material on pump tubing life is investigated. A test jig is developed which simulates the running conditions of the infusion pump for long-duration operation. Different rotor speeds and material configurations are investigated to obtain their effect on long-duration performance. Thermal effects on the roller junctions are studied and found that the Delrin silicone combination has twice the rise in junction temperature than the titanium silicone combination. The failure modes are inspected using microstructure analysis and the best configuration is identified.

Advantages of YLF host over YAG in power scaling at cryogenic temperatures: direct comparison of Yb-doped systems

We have investigated the cryogenic performance of Yb:YAG and Yb:YLF crystals in rod-geometry to understand the pros and cons of each material for the development of ultrafast lasers and amplifier systems. We have performed detailed spectroscopic (absorption, emission, lifetime), temperature, lasing, and thermal-lens measurements with Yb:YLF and Yb:YAG crystals under almost identical conditions. Our analysis has shown that despite the higher thermal conductivity of Yb:YAG, due to its smaller quantum defect, the peak/average temperatures reached under similar pumping conditions is lower in Yb:YLF crystals. Moreover, since the YLF host has a negative thermo-optic coefficient, that balances other positive contributions to thermal lensing, overall Yb:YLF rods possess a much weaker thermal lens than Yb:YAG under similar conditions. As a result of these benefits, we have shown that Yb:YLF rods perform better than Yb:YAG in cryogenic lasing experiments in terms of attainable power performance and laser output beam quality. In terms of gain per pass, the Yb:YAG medium is superior, however, the gain bandwidth is much broader in Yb:YLF systems that make it more suitable for ultrafast pulse laser/amplifier development. We have further shown that, the asymmetric thermal lens behavior of Yb:YLF favors laser operation in E//c axis over E//a axis. The comparison in this study has been performed in rod geometry and for Yb-doping, however, we believe that, to first order, the discussion could be extended to YAG/YLF laser systems doped with other ions (Pr, Nd, Er, Tm, Ho) and to other lasing geometries such as slab and thin-disk.

Conjugate heat transfer in lattice frame materials based on novel unit cell topologies

This article presents conjugate heat transfer characteristics of strut-based sandwich-type configurations obtained through reticulation of unit cell topologies of Tetrakaidecahedron, Octet and Rhombic dodecahedron shapes (porosity ∼0.90) with water as working fluid. Tetrakaidecahedron lattice exhibited the highest overall heat transfer coefficient, followed by Octet and Rhombic dodecahedron, respectively. Pressure drop was the highest for Octet, followed by Rhombic dodecahedron, and Tetrakaidecahedron, respectively. Thickness of struts in contact with endwall played a dominant role in conjugate thermal exchange of sandwich configurations. For the investigated conditions, Tetrakaidecahedron-shape based lattice provided the least thermal resistance value at any given pumping power condition.

Перспективы совершенствования центробежных насосов

The application of modern software systems and the exclusion of technological restrictions on the shape complexity can improve the energy, cavitation and mass characteristics of pumps. Plastic casings and wheels with metal frames provide increased rigidity and versatility of the units. Special coatings improve the smoothness and wear resistance of working surfaces. New shapes of axial and radial dynamic seals reduce volume losses during stabilization and the forces transmitted to the supports. The range of sensors built into the pump adjusting the mode and determining the continuous diagnostics of the pump condition increases.