Hydraulic Suspension Research Articles

Study on the hydraulic conveyance characteristics of suspended coarse particles within pipelines

The Flow Regime Transition Device transforms the gelled crude oil mass into gelled crude oil particles for hydraulic conveying. The gelled crude oil particles may reaggregate into gelled crude oil mass at the later stage of hydraulic conveying. Therefore, understanding the patterns of hydraulic suspension conveying gelled crude oil particles is vital for safely gathering and efficiently conveying crude oil. This paper employs the CFD-DEM coupling technique to conduct a numerical study on the hydraulic conveying characteristics of gelled crude oil particles. The accuracy of the model and the solution method is verified by comparing them with the experimental data of particle concentration distribution, and single particle rise behavior, and particle transport flow of gelled crude oil. The size range of gelled crude oil particles spans from 0.0001 m to 0.003 m. We operate the transportation within a velocity range of 0.5 to 4 m/s and a concentration range of 0.022 to 0.0537. Simulation results indicate two flow regimes in the hydraulic conveying of gelled crude oil particles: an upper-moving bed flow and a heterogeneous suspension flow. With increased conveying velocity, the upper moving bed flow gradually transitions to a heterogeneous suspension flow. Beneath the upper moving bed flow, some scattered particles exist, likely resulting from the action of turbulent diffusion. Changes in conveying concentration and particle size have a minor impact on the velocity distribution of particles and fluid but a more significant effect on the particle distribution across the pipe cross-section. Also, when conveying particles of different sizes, most smaller particles travel along the pipe wall.

Research on Damping Hole Optimization of Hydro-Pneumatic Suspension for Mining Trucks under Variable Load Conditions

The hydro-pneumatic suspension, known for enhancing vehicle ride comfort and stability, finds widespread use in engineering vehicles. Presently, the majority of mining trucks employ hydro-pneumatic suspension with a fixed damping hole, underscoring the critical importance of selecting appropriate damping hole parameters. Initially, an equilibrium mathematical model of the ¼ hydro-pneumatic suspension is established, and the influencing factors of the damping characteristics are analyzed. Subsequently, the simulation model and experimental bench for the hydro-pneumatic suspension are constructed. Sinusoidal signals with different frequencies and amplitudes serve as the excitation signals to analyze the variation trend of the force on the rod with displacement changes. The simulation and experimental results demonstrate a high degree of consistency, validating the rationality and validity of the simulation model. Building upon this foundation, various damping apertures are then selected to study the damping characteristics of the hydro-pneumatic suspension. The research indicates that as the damping aperture increases, the setting time of the hydro-pneumatic suspension system after excitation extends, accompanied by a decrease in the acceleration overshoot. As a result, a comprehensive evaluation index is developed, considering various factors, such as different weight setting times and peak longitudinal accelerations to assess the ride comfort of the suspension. This approach is then employed to determine the optimal damping aperture under both full-load and no-load conditions. The findings of this research offer valuable insights for the development of adaptive variable damping hydraulic suspensions, especially under variable load conditions.

Influence of rotor impeller structure on performance improvement of suspended axial flow blood pumps.

The hydrodynamic suspension structure design of the axial blood pump impeller can avoid the problems associated with using mechanical bearings. However, the particular impeller structure will impact the hydraulic performance and hemolysis of the blood pump. This article combines computational fluid dynamics (CFD) with the Lagrange particle tracking method, aiming to improve the blood pump's hydraulic and hemolysis performance. It analyzes the flow characteristics and hemolysis performance inside the pump. It optimizes the taper of the impeller hub, the number of blades, and the inclination angle of the circumferential groove at the top of the blade. Under certain rotational speed conditions, an increase in the taper of the impeller hub or the number of blades can increase the pumping pressure of a blood pump, but an increase in the number of blades will reduce the flow rate. The design of circumferential grooves at the top of the blade can increase the pumping pressure to a certain extent, with little impact on the hemolysis performance. The impeller structure is optimized based on the estimated hemolysis of each impeller model blood pump. It could be seen that when the pump blood pressure and flow rate were reached, the optimized impeller speed was reduced by 11.4%, and the estimated hemolysis value was reduced by 10.5%. In this paper, the rotor impeller structure of the blood pump was optimized to improve the hydraulic and hemolytic performance effectively, which can provide a reference for the related research of the axial flow blood pump using hydraulic suspension.

Increasing operational stability of journal bearing in hydraulic suspension micro-pump by herringbone grooved structure

Increasing operational stability of journal bearing in hydraulic suspension micro-pump by herringbone grooved structure

Measurements of rotational stiffness for precast concrete girder transport vehicles, part 2

This paper presents field measurements of the rotational stiffness of three transport vehicles equipped with different types of suspensions: leaf, combined air and leaf, and hydraulic suspensions. The rotational stiffness was determined by measuring the tilts of the vehicles when a girder or known weights were placed on them at various eccentricities. One of the tested vehicles, which featured transversely expandable wheel spacings varying from 6 to 18 ft (1.8 to 5.5 m), exhibited an increase in rotational stiffness from 78,181 to 134,584 kip-in./radian (8833 to 15,206 kN-m/radian). This paper summarizes the rotational stiffness for all the vehicles tested by the authors. The field measurements conducted have enriched the existing database on vehicle rotational stiffness in the United States.

Effects of thermal conditions on fatigue behaviour of laminated glass/epoxy plates under tension-tension cycle

The fatigue behavior study on laminated glass/epoxy composite plates at elevated temperature is attempted in the present research work. INSTRON 8862 servo-electric universal testing machine with hydraulic suspension is utilized to perform low cyclic tension-tension fatigue tests at 0.5Hz and 0.7Hz frequencies. Bluehill universal software compatible with INSTRON 8862 is employed to obtain the relationship of fatigue stress upon cycles to failure (S – N) for each specimen. The parametric investigation is done for the loading frequency, lamination sequence and number of layers to understand their effects on fatigue behavior of composite laminated plates under ambient and thermal environment. The elicited results lead to the conclusion that above parameters greatly influenced the fatigue behavior of composite laminated plates under thermal loading. The rising temperature has significant adverse effects on fatigue life. The present research is beneficial for the analysis and design of laminated composite plate or plate-like structures in the domain of fatigue analysis.

Multidomain Synthesis of Optimal Vibration Suppression Systems

Abstract There are numerous design possibilities for vibration–suppression systems considering components from multiple domains (e.g., mechanical, hydraulic, pneumatic, electrical). Traditional vibration absorber design approach could only explore limited possibilities, of which the performance is away from optimal. Since the 2000s, network synthesis-based approach has been applied. It allows identification of optimal absorber properties represented by networks consisting of modeling elements (stiffness, damping, inertance), providing significant theoretical performance improvements. However, such improvements have not yet been realized in industry. This is because the following questions have not been answered: (1) What are the network-represented properties of the conventional absorber? (2) How can the optimal network-represented properties be realized considering multidomain physical components? This article provides a method for answering these questions by proposing a novel multidomain synthesis technique, allowing bidirectional transformation between networks and multidomain components. Building on this technique, a vibration–absorber design methodology is proposed, which can construct physical realizations of optimal absorbers considering multidomain components. Another contribution of this work is to propose a novel component, providing a hydraulic realization of compliance ‘embedded’ in a hydraulic network. This methodology is demonstrated using an automotive case study, where the constructed optimal hydraulic suspension provides 23% ride comfort enhancement over the conventional one.

DESIGN FEATURES OF CASE AGRICULTURAL TRACTORS

Leading firms and corporations - manufacturers of agricultural machinery (hereinafter referred to as companies) develop, produce, and then offer tractor models on the market in the form of construction series combining up to 40-55 models. The largest companies produce not only tractors, but also sets of agricultural machines for them, as well as entire technological complexes for processing and harvesting one or another crop. Thus, these companies act on the markets with their own product programs, which include the construction series of tractors as the most important component (Deere & Co, Case, New Holland, Massey Ferguson, etc.). Each construction series includes several (up to 10) series (families) of tractor models, identical in purpose, differing in engine power. The basis of each such family is unified aggregates and units - engines, transmissions, front and rear axles, hydraulic suspension systems, cabins, electrical equipment and other aggregates. The tractors of the construction series have a single stylistic solution of the cabin and external structure, which is a trademark. The construction series is characterized by a high saturation of models, especially in the range of small and medium capacities, which is explained by the increased demand for tractors of these capacities. The redundancy of models is especially noticeable in the design series of companies that were formed by merging companies that previously had their own design series (for example, the Case New Holland Company). Design series are built according to engine power and tractor weight, series - according to engine power, the gradation of which is determined by the number of engine cylinders and the possibility of forcing it with the help of low or high turbocharging. Often, the models of the series, and especially the series, have very little difference in engine power, which, with the redundancy of a number of models, allows companies to meet the demands of the maximum number of consumers for tractor performance and fuel consumption in competitive conditions.

On calculational analysis of suspensions with hydraulic springs

BACKGROUND: The information about application of hydraulic springs in suspension systems of tanks and self-propelled artillery weapons may be found in domestic scientific and nonfiction literature. In addition, machines, which prototypes were equipped with this type of suspension, are known. For instance, possibility of hydraulic suspension implementation was proven on the T-34 tank prorotype, whereas application of this type of suspension with heavy tanks gave the most prospectivity. Complication of sealing build-up with sufficient life span, development of technologies of metal springs strengthening and shutdown of heavy tanks development did not allowed hydraulic suspensions to become widespread. At present, they are not used at all, whereas methods of analytical calculation are not in public access, despite of the interest of a group of scientists. AIMS: Development of the method of determination of main parameters of suspensions with hydraulic springs and analysis of properties of the T-34-76 Soviet middle tank prototype hydraulic suspension from the point of modern theory of nonlinear suspension systems. METHODS: Justification and confidence of given dependencies for properties calculation, conclusions and recommendations are confirmed with application of strict mathematical apparatus of mechanics, hydraulics and thermodynamics as well as scientifically justified theoretical backgrounds. RESULTS: Historic data on liquids compressibility researches, method of analytical determination of main properties of hydraulic springs with various design schemes, allowing restoring of properties of suspensions of existing tracked vehicles, synthesizing properties of other suspensions and, moreover, estimating reasonability of properties of suspension with hydraulic springs, are presented in the article. According to the method, proposed in the article, properties of the hydraulic spring from the T-34-76 Soviet middle tank prototype, equipped with hydraulic suspension, were restored and analyzed. In addition, suspension properties for the same vehicle were synthesized and used for a comparative analysis. CONCLUSIONS: The information, presented in the article, is helpful for research engineers, interested in study of elastic behavior of liquids in case of their application in suspension systems, whereas the proposed method, allowing synthesis of reasonable properties of hydraulic springs, gives an opportunity to study the ride comfort of tank propotypes, equipped with hydraulic suspension, with a good quality and, moreover, to synthesize hydraulic springs properties according to the demands, given to a design engineer.

A hybrid sliding mode controller design for vibration suppression in a hydraulic suspension system with vertical load disturbance

Anti-disturbance vibration control is a crucial component in a hydraulic suspension system. However, random input excitation and prolonged service can cause hydraulic suspension system parameters to drift, leading to system vibration with suppression failure. The resulting states of nonlinearity and disturbance will lead to a gradual deterioration of pressure control. Therefore, designing a viable controller for a hydraulic suspension system that considers system nonlinearity, computing capacity, and sensor configuration is essential. To address this need, we present a double-layer control strategy in this work. A hybrid sliding mode control algorithm based on the reference skyhook and groundhook model is proposed to regulate the expected force of reverse compensation. An output controller is then applied based on the expected force observer to mitigate low-frequency vibrations to realize a steady state. A logic rule is designed to ensure that the two controllers work to suppress sprung mass vibration, and a comprehensive system model is derived to help characterize system nonlinearities and design the hybrid sliding model controller. Numerical and physical validations are then carried out to demonstrate the feasibility of the strategy and test the performance of the controller. The experimental results show that the hybrid sliding mode controller can suppress vibration under disturbance excitation and reduce the vibration acceleration to a 2.3 m/s2 random response when system parameters vary.

Regenerative hydraulic SUSPENSION: Numerical model and Evaluation of Energy Harvesting Potential using bond graphs

ABSTRACT This paper presents a novel nonlinear bond graph model of the regenerative hydraulic suspension system. The model has been developed in a way that closely follows the physical structure of the underlying system. The proposed regenerative hydraulic suspension bond graph model was simulated for the mathematical approximation of E class road profile according to the ISO 2631–1 standard (10 mm and 3.81 Hz excitation parameters). The obtained simulation results show that the proposed regenerative suspension system can effectively isolate vibrations even on a poor road at a relatively high excitation frequency. The reduction of the vehicle chassis velocity relative to the velocity of the input signal is about 62% (for selected simulation parameters). The proposed regenerative hydraulic system can regenerate a maximum electrical power of 23.9 W and an average electrical power of 19.84 W in an electric generator for a 10 s simulation test. This type of device is more practical to use on lower quality roads for the category of heavy vehicles due to the compromise of vehicle driving comfort and useful power regeneration.

Analytical solutions of the energy harvesting potential from vehicle vertical vibration based on statistical energy conservation

Two kinds of approaches have been proposed to harvest the vibrational energy from a running vehicle, namely using a regenerative damper to replace a traditional hydraulic suspension damper, or adding one or more dynamic vibration absorbers (DVAs). Extensive studies have been conducted by simulation or experiment on the first approach, whereas the studies on the second approach are very limited and even the energy harvesting potential is not clear. This paper tries to present an analytical solution, to uniformly reveal the energy harvesting potential from vehicle vertical vibration by both approaches, with a focus on approaches with DVAs. A generic quarter car model is proposed to represent various vibration energy harvesting configurations. With a newly enunciated statistical energy conservation property for linear vibration systems, the analytical solution of the energy harvesting potential is derived for the proposed model subjected to random excitation. It is illustrated from these analytical expressions that the total vehicle vertical vibration energy is not directly related to DVA configurations, and the vibration energy dissipated in the tire can be transferred to the absorbers. Literature results and newly implemented statistical analyses are presented to validate and demonstrate the derived solutions. Sensitivity analysis is then performed to reveal the effect of various vehicle parameters on the energy harvesting potential.

Comparison the Hydraulic Harvested Energy with the Electromagnetic Systems and the Spent Energy on the Active System

An energy-harvesting hydraulic regeneration suspension system is described in this article, which includes a hydraulic motor, a spool valves, and a hydraulic cylinder. Regenerative actuators are built using a hydraulic transmission system as their inspiration. The proposed regenerative actuator is implemented in the vehicle's non-linear suspension system for a complete model. MATLAB Simulink is utilized to generate and simulate the entire vehicle's regenerative suspension system, which has force properties which are nonlinear with hydraulic actuators equations with energy harvesting from regenerative actuators. During the mathematical simulation, the effect of pressure differential on the spool valve's operation is also taken into account. The quantity of captured energy is compared to the energy expended on the active actuator and the energy generated with the electromagnetic actuator at three distinct input signals at three different pressure level (10, 30 and 50 bars) (random, sinusoidal, and square). The energy generated in the regenerative hydraulic actuator at three pressure levels behaves the same as the active actuator in terms of response, plus the highest pressure of 50 bar is closely comparable to the active system in terms of energy harvest and gradually decreases as the output pressure drops in addition to the behavior of the electromagnetic and its comparison with the wasted energy of the active system.

Influence of circumferential annular grooving design of impeller on suspended fluid force of axial flow blood pump.

Aiming at insufficient suspension force on the impeller when the hydraulic suspension axial flow blood pump is start at low speed, the impeller suspension stability is poor, and can't quickly enter the suspended working state. By establishing the mathematical model of the suspension force on the impeller, then the influence of the circumferential groove depth of the impeller on the suspension force is analyzed, and the annular groove depth on the impeller blade in the direction of fluid inlet and outlet was determined as (0.26, 0.02 mm). When the blood pump starts, there is an eccentricity between the impeller and the pump tube, the relationship between the suspension force and the speed of the impeller under different eccentricities is analyzed. Combined with the prototype experiment, the circumferential annular grooving design of the impeller can make the blood pump rotate at about 3500 rpm into the suspension state, when the impeller is at 8000 rpm, the impeller can basically achieve stable suspension at the eccentricity of 0.1 mm in the gravity direction, indicating that the reasonable circumferential annular grooving design of the impeller can effectively improve the suspension hydraulic force of the impeller and improve the stability of the hydraulic suspension axial flow blood pump.

Position Control Algorithm of Fuzzy Adaptive PID of Hydraulic Interconnected Suspension Under Load Impact Disturbance

Position control accuracy of hydraulic interconnected suspension (HIS) for agricultural vehicle is unsatisfied under load impact conditions. In order to address this problem, advanced control methods were studied in this paper. The technical scheme of HIS was developed firstly. The transfer function from proportional valve spool displacement to hydraulic cylinder piston displacement was derived and then the parameters of the transfer function were also identified. The PID, sliding mode control (SMC) and fuzzy adaptive PID (FAPID) control algorithms were designed. The co-simulation of AMESim and SIMULINK was adopted to compare and analyze the control characteristics of the three algorithms. An experimental platform was also built to verify the improvement effect. The research conclusions show that when the HIS operates under load impact condition, for FAPID algorithm, the rise time is reduced by 0.27s, the maximum overshoot is reduced by 9.83mm, and the absolute value of average error is decreased by 62.62% compared with PID control algorithm. The response speed of SMC is the fastest, but there is a large chattering in the steady-state displacement. The designed FAPID control algorithm balances the advantages of fast response, high control precision and good stability, and the control performance is better than that of SMC and PID control algorithms. The research methods in this paper can provide reference value for position control accuracy improvement of hydraulic suspension.

USE OF MODIFIED REAGENTS SOLUTIONS WHEN PREPARING DRINKING WATER

Currently, attention is paid to the intensification of the process of natural and wastewater treatment, improvement of technology, development of new effective methods of intensification of water treatment. This will simplify the existing technology of water treatment, reduce labor-intensive processes of preparation and dosing of reagents, reduce the cost of operating treatment plants, increase their productivity, improve quality and reduce the cost of treated water. Treatment of water with a modified coagulant solution allows to increase the hydraulic size of the coagulated suspension. The strongest effect of the modified coagulant solution has on the hydraulic suspension size of 0.2 mm/s and less, i.e. the smallest and the suspension, which is difficult to remove, which creates conditions for more intensive sedimentation in settling tanks and improve the quality of water clarification and fed to fast filters. It has been experimentally determined that the treatment of water with a modified solution of aluminum sulfate coagulant should be performed when the content of suspended solids in the clarified water is up to 100–150 mg / dm3. The color of the clarified water during treatment with a modified solution of aluminum sulfate coagulant does not depend on the content of suspended solids and is 1.5-1.6 times lower than the color than when using a conventional coagulant solution. It is established that the use of a modified solution of aluminum sulfate coagulant in water purification can reduce the residual aluminum content in clarified water by an average of 50-60%. The results of researches of the modified solutions of reagents which are used at preparation of drinking water are presented. It is established that water treatment with a modified solution of aluminum sulfate coagulant allows to improve the quality of drinking water preparation by suspended solids, color, reduce the content of aluminum salts in the clarified water, thereby increasing the environmental safety of drinking water.

Design and test of hydro-pneumatic ISD suspension in heavy multi-axle vehicles

Aiming to improve the road friendliness so as to reduce the road damage caused by heavy multi-axle vehicles, and to enhance the ride comfort, we propose a kind of hydro-pneumatic ISD suspension structure, which is equivalent to a two-stage ISD structure integrating a traditional hydro-pneumatic suspension and a fluid inerter. Firstly, based on the 1/4 model, a genetic algorithm is used to optimize the key structural parameters of hydro-pneumatic ISD suspension. Secondly, the AMESim dynamic model of heavy multi-axle vehicles is built for the performance comparison between the traditional hydraulic and hydro-pneumatic ISD suspensions. Finally, this paper machines a hydro-pneumatic ISD suspension to replace the traditional hydraulic one in a heavy multi-axle vehicle to carry out a road test. Test results indicate that the proposed suspension can effectively restrain the vibrations of sprung and unsprung mass and improve ride comfort as well as road friendliness. The hydro-pneumatic ISD suspension can be applied to engineering.

Analysis and design of auto-adaptive leveling hydraulic suspension for agricultural robot

The application of agricultural robot in hilly and mountain areas faces several problems, such as bad walking performance, easy tilt, and low safety. The auto-adaptive leveling hydraulic suspension for the agricultural robot can help to eliminate some sort of problems. The design of such system is the main aim of the article. The hydraulic system with load-sensing system and its controlling model were established and then the load-sensing system was modeled and simulated in Advanced Modeling Environment for SIMulation. The optimal proportional–integral–derivative parameters were determined by the optimized algorithm. The simulation results illustrated that the inlet and outlet pressure difference of throttle and the flow rate through throttle are 42 bar and 29.65 L/min, respectively, all the time when the load pressure varies from 0 bar to 100 bar. The load-sensing system has good power follow-up and high control accuracy. And then the experimental bench of auto-adaptive leveling hydraulic suspension was researched and developed to verify the leveling performance. The experimental results demonstrate that auto-adaptive leveling hydraulic suspension can keep frame leveling dynamically on upslope, downslope, side slope, and continuous undulating road surface. The maximum errors of the pitch angle and the tilt angle are −0.93° and 0.97°. The feasibility of the designed hydraulic suspension was verified. The research methods in this article can provide theoretical basis for the design of other auto-adaptive leveling systems in hilly and mountain areas.

Configuration development and optimization of hydraulically interconnected suspension for handling and ride enhancement

In this study, among 180 possible hydraulically interconnected suspension configurations, non-symmetric cases were eliminated and 24 potential configurations were selected for further investigation. A 14-DOF vehicle model capable of generating handling and ride motions is developed. At different manoeuvres and road inputs, the handling and ride performances are investigated for 24 configurations. Six hydraulic parameters are then optimized by the application of genetic algorithm in order to improve the ride. The handling performance is also investigated and results have shown that only four configurations provide better ride and handling performances simultaneously. The bounce acceleration response is shown to be reduced up to 47% for the four selected configurations. The roll and pitch angle responses were also reduced around 3% and 18% respectively. Four optimized configurations were also investigated under two sever ride and handling manoeuvres. It is shown that, for the vehicle with the optimized interconnected hydraulic suspension, the bounce acceleration response for a random road test is reduced up to 27% and the roll angle is reduced up to 18% for a side wind test.

Simulation of Hydraulic Suspension System of Electric Tractor Based on Matlab-AMESim

For electric tractor engine power output characteristic, a load sensitive hydraulic suspension system in front of the valve is designed. In order to meet the operation requirements of different soil conditions when the electric tractor is plowing, and to improve the dynamic response characteristics of the system and the uniformity of tillage depth, a fuzzy PID based resistance-position combined adjustment tillage depth control strategy is designed. The hydraulic system simulation model is established based on AMESim, and the fuzzy PID controller model is established using Matlab. Through the joint simulation of AMESim and Matlab, the control performance of hydraulic suspension system of electric tractor with different resistance-position comprehensive proportional coefficients is analyzed. The simulation results show that the control strategy of tillage depth based on fuzzy PID is more responsive and anti-interference strong ability, the resistance-position combined adjustment has higher adaptability to different soil changes and operation methods than a single resistance adjustment or position adjustment.