Hydraulic Impulse Research Articles

Increasing the efficiency of choosing a hydraulic impulse drive with programmable control

Increasing the efficiency of choosing a hydraulic impulse drive with programmable control

Increasing the efficiency of choosing a hydraulic impulse drive with programmable control

Increasing the efficiency of choosing a hydraulic impulse drive with programmable control

THE LATEST TRENDS IN THE CREATION OF IMPACT-VIBRATION EQUIPMENT WITH DIFFERENT TYPES OF DRIVES FOR SOIL PROBING

The study of soils by immersion of a cone under the influence of ultrasonography is one of the express methods of obtaining engineering and geological information about the physical and mechanical properties of the foundation from loose soils of buildings and structures. It makes it possible to detect the degree of homogeneity of probed soils; determine the position of the boundaries (contacts) of various lithological layers and bearing layers for the fuel base; to identify and delineate in plan and in depth the weakened zones on the studied areas for the exact reference of the place of conducting experimental works; choose the optimal options for choosing hammers; evaluate the physical and mechanical properties of sandy soils (density, angle of internal friction, etc.); roughly estimate the modulus of deformation of sandy soils. The main tasks are the development, research and calculation of the main parameters of installations with a hydraulic impulse drive for soil probing. The object of research is the process of soil probing. The subject of the study is the hydropulse drive of the soil probing installation. Experience has shown that the effective use of field methods is possible only under the condition of a methodically correct approach to the preparation and execution of programs of the entire complex of search operations. Various aspects of the problem of comprehensive soil research using field methods were developed and deepened gradually.The main research methods include the analysis of information on existing methods and installations for spraying tungsten powders, mathematical modeling of processes in the spindle unit of the installation for spraying metal powders, taking into account its design features and operating modes based on nonlinear differential equations of heat transfer from solid and liquid bodies using numerical methods of their solution based on the FlowVision program.

Modelling of Piling Technology by Vibroimpact Device with Hydropulse Drive

Based on the analysis of the developed mathematical model, this paper proposes optimal operating modes of the vibroimpact device to ensure the intensification of driving construction piles. It is an original design of a modern, highly efficient device for driving construction piles, equipped with a compact, powerful hydraulic impulse drive unit. To develop a mathematical model of the construction pile driving technology, the following methods were used: mechanoreological phenomenology, hydrodynamics, and generalised laws of mechanics. Mathematical models of the dynamics of technological processes of driving construction piles with a vibroimpact device are improved based on a hydraulic impulse drive unit in the form of a spatial non-stationary formulation of the problem and integral equations of dynamic characteristics of the moving elements of the drive unit. The study obtained the distribution of the pressure and velocity of the working fluid in the hydraulic unit of the vibroimpact device, as well as changes in the kinematic parameters of the elements of the technological equipment based on the mathematical model developed by the finite volume method, using numerical modelling and high-performance computer systems. Optimal modes of operation of a hydraulic impulse drive of a vibroimpact device are proposed to provide an intensification of the construction pile driving technology. It was found that when low-frequency vibration is applied, the driving of construction piles is intensified. Application of a hydraulic impulse drive that is based on two-stage vibration excitation allowed implementing the vibroimpact modes of the device. The average pile driving speed with a vibroimpact interaction is five times higher compared to conventional driving methods

RESEARCH OF EFFICIENCY PARAMETERS OF PROCESSES OF CLASSIFICATION OF DRY CEREAL RAW MATERIALS WHEN USING DIFFERENT SCHEMES OF ITS LOADING

The classification processes (separation, sorting, separation, fractionation) of dry dispersed materials are quite common in the food, chemical and processing industries, in agriculture, metallurgy, at machine-building enterprises and in construction. In particular, at food enterprises, two groups of these processes are implemented - for the extraction of fractions with particles of various sizes, shapes, densities, aerodynamic or electromagnetic properties from raw materials, or for cleaning the raw materials from impurities (sand, stones, metal particles). At the moment, a large number of methods and methods of classification (mechanical, hydraulic, pneumatic, electrophysical) and types of equipment for their implementation (screens, screeners, triers, drum screens, hydraulic, pneumatic and electromagnetic separators) are known, in this regard, an urgent task is to choose for a specific type of raw material and technology, of the most rational method of classification and equipment for its implementation. The article presents equations and dependencies for determining the time and energy consumption in the implementation of the processes of mechanical classification of grain raw materials using various load schemes using the most common equipment. At the same time, the classification processes carried out under the influence of gravitational or centrifugal forces, vibration effects, and the load created by a hydraulic impulse or electromagnetic drive are compared. As the main operating parameters of the processes, the maximum speed of movement of a particle of the processed material and the energy intensity of the classification were selected. A computer program can be created with using of the proposed dependencies, to develop a rational classification technology, taking into account the physical and mechanical characteristics of the processed raw materials and specific production conditions.

Investigation of Impulse Oscillometry for the Detection of Extravasations using Design of Experiments and an Infusion Simulator

Extravasation is a phenomenon that occurs when the infusion solution misses the vein and enters the surrounding tissue. We developed a sensor prototype utilising impulse oscillometry to detect extravasations at an early stage. A hydraulic impulse is injected into the infusion line to observe and analyse its progress. The aim of this study was to determine the tissue parameters that might influence the sensor measurement signal and signal changes during extravasation.We developed a simulator that simulates infusions and extravasations to test the prototype. Tissue-specific parameters can be adjusted independently.The effects of the tissue parameters, including blood pressure, blood flow, blood density, blood viscosity, vein diameter, venous wall thickness, and tissue modulus of elasticity, were investigated using the design of experiments method. The parameter values were varied between two levels and tested across 16 experiments.Blood pressure, blood viscosity, vein diameter, and venous compliance demonstrated the greatest impact on the sensor signal (p < .001). The other parameters showed negligible effects. Significant differences (p = .006) in the pressure signal of the sensor could be observed when the catheter changed from the venous position to the extravasal position.

New Hydraulic High-Pressure Impulse Generator for Long-Duration Impulse Tests

Water hammer wave is widely applied to test hydraulic components in various areas. A new hydraulic high-pressure impulse generator is presented in this paper in order to provide the standard water hammer wave for long-term usage. A combination of a sleeve and a rotary spool was used to build the impulse generator, and a booster piston was applied to amplify the output pressure. Mathematical models were established using commercial software, and a prototype and a test rig were built based on the simulation results. The experimental results for both single wave and repeated periods show the feasibility of the new design and indicate that the new hydraulic high-pressure impulse generator can be used for long-time impulse tests.

New solutions to the problems of stripping of ore bodies using inclined workings driven downward in conditions of increased water cut

The authors of this paper describe the face transport system that ensures the stripping of ore bodies using the underground development method with inclined narrow workings driven downward, including in conditions of increased water cut. The face transport system will allow the preparation of a new 500-thousand-ton mine with minimum general construction and mining construction works as well. The article contains an engineering study of the transition of the road heading to blastless continuous-flow methods of rock development using hydraulic impulse or mechanical shock machines, which are under development. For deep and ultra-deep developments starting from 250-300 m and deeper, a new technical solution is given for the construction of a downhole mine airlift with the lowest capital and operating costs and sufficiently high reliability and productivity. New technical solutions will ensure the radical transition of the technological concept of mining production from the drilling-and-blasting cyclic to blastless continuous-flow one.

MODERN TECHNOLOGIES FOR LOADING AND UNLOADING WORKS ON MOBILE AUTOMOBILE TRANSPORT

In this work, vibrations were investigated during loading and unloading operations of mobile agricultural machines, which are considered to be one of the most labor-intensive components of the transport process. Therefore, idle machines during carrying out operations and in anticipation of them remain quite significant, which is due to the insufficient level of mechanization of loading and unloading of cargoes on transport, with a fuzzy coordination of actions of different organizations during the overloading of cargoes at transport nodes and for some other reasons. The main means of mechanization are stationary and gantry cranes for containers, heavy loads and large packages, as well as means of mechanization on the railway or on the chassis of a standard mobile car or special chassisIn our opinion, the use of hydraulic impulse actuators in the production of vibration and vibration shock unloading devices, which is due to simplicity of design, compactness, high energy intensity, a wide range of regulation of operating parameters and the ability to work in an automated mode is promising. In particular, a promising area is the creation of removable attachments with hydraulic impulse drive for dump trucks, onboard vehicles, tractor trailers and other vehicles. For intensification of processes of unloading of a body of a trailer-dump truck of tractors the hydraulic vibrating shock device is developed. It accelerates the unloading and cleaning of the body of agricultural products. Reduced costs and reduced oversized idle tractors with unloading trailers. Therefore, the development of vibration and vibration impact equipment for use in loading and unloading operations on mobile agricultural machines and in general on transport is an urgent task.

VIBRATION RESEARCH IN MOBILE AGRICULTURAL MACHINES

In this work, vibrations were investigated during loading and unloading operations of mobile agricultural machines, which are considered to be one of the most labor-intensive components of the transport process. Therefore, idle machines during carrying out operations and in anticipation of them remain quite significant, which is due to the insufficient level of mechanization of loading and unloading of cargoes on transport, with a fuzzy coordination of actions of different organizations in the overloading of loads at transport nodes and for some other reasons. The main means of mechanization are stationary and gantry cranes for containers, heavy loads and large packages, as well as means of mechanization on the railway or on the chassis of a standard mobile car or special chassis. In our opinion, the use of hydraulic impulse actuators in the production of vibration and vibration shock unloading devices is promising, due to the simplicity of construction, compactness, high energy intensity, a wide range of regulation of operating parameters and the ability to work in automated mode. In particular, a promising area is the creation of removable attachments with hydro-impulse drive for dump trucks, onboard vehicles, tractor trailers and other vehicles. For intensification of processes of unloading of a body of a trailer-dump truck of tractors the hydraulic vibrating shock device is developed. It accelerates the unloading and cleaning of the body of agricultural products. Reduced costs and reduced oversized idle tractors with unloading trailers. Therefore, the development of vibration and vibration impact equipment for use in loading and unloading operations on mobile agricultural machines and in general on transport is an urgent task.

Automatic packer reliability prediction under pulsed transient flooding of hydrocarbon reservoirs

For pulsed transient flooding of hydrocarbon deposits (installed on the tubing string below the packer) of the injection well, hydraulic impulse devices are used. When they work (generation of pulses in the injected fluid) in the tubing string, hydraulic shocks occur at a frequency equal to the output frequency of pulses generated by the devices. The result is a reciprocating movement of the tubing string and the packer. Hence, for effective injection of fluid, it is necessary to provide automated long-term reliability of the sealing elements of the packer and long-term sealing of the annular space. Joint movement of the packer and pressure pulsation intensify mechanochemical aging processes. To improve durability of packer seals during long-term pulsed injection of fluid into the well, it is necessary to replace rubber materials with rubber-fabric materials and use damping equipment along with impulse devices. Their use will significantly reduce the amplitude of packer oscillation (stroke length of sealing element S) and maximum accumulation time Wmax.

Fluid Flow Rate under Hydraulic Impulse Effect on Well Bottom Zone in Oil Reservoir

The solution is presented for the problem on oil percolation in a reservoir at the present and time-varying pressure difference between the injection and production wells. The area of water blocking under capillary pressure in the well bottom zone is determined. The algorithm is proposed for calculating fluid pressure on the well bottom by readings of echo sounder installed at the well mouth. The penetration zone of pressure fluctuations in the reservoir is estimated, and their effect on enhanced well production is shown.

Recharge Impulse Spreading in Western Carpathian’s Mountainous Fissure–Karst Aquifer

Foreseen construction of a highway tunnel in the northern part of the Veľká Fatra Mts. (Slovakia) triggered the need for extensive hydrogeological investigations. The projected tunnel axis would cut through a large body buildup of Middle Triassic carbonate rocks. Dolomites and limestones with fissure–karstic permeability are surrounded by less-permeable marls, so that all springs dewatering this uplifted plate of carbonates are found above the erosion base on its edges. Detailed, hourly-based discharge monitoring of all four major springs was performed during the spring and summer period of 2014. In the meantime, groundwater table observations in two boreholes, located in the center of the fissure–karst aquifer, were run in the same time interval. Based on air temperature and precipitation records, the 2013–2014 winter period was practically without snow cover. In the middle of March 2014, an intense rainfall event caused a sudden rise of the groundwater table in the TK-04 borehole located in the southern part of the carbonate plate. Spreading of this singular hydraulic impulse throughout the structure was differently registered at individual springs within the time shift span of 1.38 to 65.25 days. Groundwater level rise of 0.40 m in the TK-04 borehole was postponed in 5.33 days. The response time of spring discharge to sudden groundwater table rise within the structure occurred later at springs with a higher water temperature. Water temperature differences between individual springs were still within the 2.46 °C narrow interval (5.57–8.03 °C). The vertical component of groundwater flux should play an important role even in a relatively simple, plate-shaped mountainous karstic aquifer fully uplifted above the erosional base, as was the case of the investigated Kopa Mt. hydrogeological structure.

Terms of the stability for the control valve of the hydraulic impulse drive of vibrating and vibro-impact machines

Terms of the stability for the control valve of the hydraulic impulse drive of vibrating and vibro-impact machines

Minimising the air demand of micro-hydro impulse turbines in counter pressure operation

Following new and innovative concepts of energy recovery which use micro-hydro impulse turbines in drinking water systems, more sophisticated turbine designs become essential to improve energy recovery efficiency. In the case of implementing a hydraulic impulse turbine with tailwater depression in such systems, one major challenge to optimising overall efficiency is the reduction of the turbine's air demand. Firstly, a lower air demand would reduce the required dimensions of the ventilation system and therefore increase energy efficiency. Secondly, a minimised air demand would considerably reduce negative effects downstream of the turbine casing, such as a reduced transport capacity and corrosion. To achieve a minimised air demand, detailed experimental investigations are conducted, during which different casing inserts are tested in a micro-hydro Pelton machine. A specially constructed turbine test-bed, featuring two separately installed measuring units, allows for the partitioning and measurement of dissolved and undissolved air. In the case of the used Pelton machine, the results clearly identify different air detrainment processes. The undissolved air demand strongly depends on the particular casing insert and can be reduced by 90% through optimal flow condition using flow straighteners as insert. In contrast, the amount of dissolved air demand cannot be controlled by additional casing inserts. This can be explained due its different entrainment processes. The analysis of the dependency of the measurement results on scale shows that a direct transfer to a prototype application will underestimate the air demand. Nevertheless, the presented research findings show an effective way, also relevant to turbine manufacturers, to reduce air demand and improve overall efficiency of impulse turbines in counter pressure operation.

Penetration depth of plunging liquid jets – A data driven modelling approach

In the case of impinging water jets or droplets, air entrainment processes are crucial to the casing design of hydraulic impulse turbines in the micro-hydro sector. To initiate first steps towards a precise prediction of the complex, multi-phase casing flow of impulse turbines, single aspects such as the penetration depth of impinging liquid jets have to be separated and fully understood. Existing investigations determining penetration depths are related to a very small range of flow rates and therefore show an underestimation of the penetration depth being applied to the casing flow of impulse turbines, which are generally operated at higher flow rates. For a more general description of the air entrainment process, investigations of plunging water jets within an extended flow rate range are conducted and the penetration depth is modelled using a data driven artificial neural network (ANN) approach and a non-linear regression model.At low flow rates, experiments results are in accordance with existing studies, whereas penetration depths up to 170cm are measured at higher flow rates. For the mathematical models to achieve a wide range applicability, a large data base is used, including published and measured data. The modelled penetration depths can be precisely verified by the performed measurements and show correct physical behaviour, even in areas without underlying data. Calculation rules, weight matrices and biases of the trained ANN are published to achieve high transparency and scientific improvement in neural modelling of penetration depths of impinging liquid jets.

Study of an Energy Regeneration System with Accumulator for Hydraulic Impulse Testing Equipment

To guarantee the reliability and performance of hydraulic systems, it is of vital importance to do hydraulic impulse testing for hydraulic components. However, the testing time is usually so long that the energy consumption is very large. An energy regeneration system with an accumulator is proposed and used for hydraulic impulse testing equipment. Mathematical analysis and simulations show that the hydraulic impulse testing system with an accumulator can reduce energy consumption by 15% compared with that of the system without an accumulator in the cycle. Furthermore, the energy efficiency of the hydraulic impulse testing system is increased from 62.82 to 75.71% by the use of an accumulator. Both simulation results and experimental results show that the control performance of the hydraulic impulse testing equipment with an accumulator is better than that of the equipment without an accumulator, and has a faster response speed and a larger pressure rise rate.

The hydraulic ram (or impulse) pump

The hydraulic impulse pump utilizes a fraction of the momentum of a flowing stream to lift a small portion of that water to a higher level. There it may be accumulated in an elevated cistern to provide sufficient water for several families, for the pump works 24 h a day with no additional source of energy. The operation of the pump is described, along with a working demonstration model constructed from plastic waste pipe and fittings.

Research on Key Technology of Hydraulic Impulse Testing Equipment

Aiming at the ability of the key technology problem of hydraulic impulse-testing equipment to reliably and controllably produce standard hydraulic pulse, on the basis of the pipe-cubage model, a ramp model has been established for the first time, and the response expression of ramp input has been deduced. The computation results indicate that the maximum adjustable excess of a ramp-input model is 67.7%. According to the step-input and the ramp-input models, theoretical analysis shows that the ramp-input signal can be treated as a step-input signal when the time of ramp input is less than one-tenth of system oscillation periods, and the simulation results indicate that the difference of the maximal excess of both ramp and step models is no more than 7%. Both the step-input and ramp-input models have carried out digital simulations using software and the electrohydraulic assimilation method. The simulation results show that by adjusting pipe-cubage model system parameters, such as cubage, length of pipe, an...

Comparative analysis of the operation of filtration fish protective devices

1. The hydraulic-biological and geometric criteria of a comparative evaluation of various designs of filtration fish protection devices (FPDs) with a fish diversion were formulated and brought to practical use. These criteri a permit a uniform approach to the development of effective FPDs and obtaining economical and reliable means of protecting fishes in the presence of water intakes. 2. A new method of hydraulic calculation of an obstacle obliquely installed in a flow with a fish diversion was developed, which permits taking into account the nonuniform distribution of the normal components of the flow velocities through a screen over its length. Theoretical investigations made it possible to obtain for the first time exact relations of the coefficient of resistance of the screen itself ξ=(2−2A)/A, where A is the coefficient of the cross section of the screen, and of the coefficient of resistance of the screen installed at angle θ to the approach flow ξs=ξ sin2 θ+1, and also the relation for the angle of emergence of the flow from the screen mesh β=arctg [(1−A)×tg θ/(A+tg2θ)]. 3. The results of analyzing various schemes of FPDs with the use of the hydraulic-biological and geometric criteria showed that FPDs with a fish diversion and three-dimensional reticulate barrier in the form of conical two-cavity surfaces most completely meet the requirements of fish protection at water intakes. 4. Two methods of cleaning the screen are most prospective: by the through-going flow with rotation of the barrier and hydraulic impulse cleaning.