Optimization of valve plate applied in secondary unit and noise reduction

2021 ◽  
pp. 095440622199840
Author(s):  
Li Tan ◽  
Haibo Xie ◽  
Gang Xiao ◽  
Herong Tang ◽  
Yuenian Li ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Simulation Models ◽  
Valve Plate ◽  
Critical Parameters ◽  
Cylinder Pressure ◽  
Test Bed ◽  
Flow Ripple ◽  
Mobile Crane ◽  
Motor Condition ◽  
Set Up

Secondary unit, in term of application, is the combination of pump and motor, the valve plate specifically designed for pump or motor may not be suitable for a secondary unit. This paper mainly discusses design of valve plate of secondary unit applied in mobile crane, several critical points needed to be noticed during design have been discussed, furthermore, by adopting the proposed method to optimize a valve plate, which originates from closed-loop pump and now is used in opened-loop system, noise reduction was realized. Firstly, 1D simulation models, including pump condition and motor condition, were established in AMESim to obtain cylinder pressure, flow ripple and other critical parameters; secondly, by using Pumplinx, 3D numerical simulation was conducted to evaluate the cavitation risk; finally, a test bed was set up to validate the simulation result. Simulation result agreed well with the tested one. Both of them verified practicability of the proposed method. This research may provide a guidance for engineers and scholars who are interested in pump and motor.

Effects of spray inoculation equipment on the viability of Rhizobium spp. in liquid inoculants for legumes

1982 ◽  
Vol 22 (117) ◽  
pp. 299 ◽  
Author(s):  
RR Gault ◽  
DL Chase ◽  
J Brockwell
Keyword(s):  
Soybean Seed ◽  
Strain Differences ◽  
Significant Loss ◽  
Operating Pressure ◽  
Test Bed ◽  
Spray Inoculation ◽  
Rhizobium Spp ◽  
Set Up ◽  
Pumping Equipment ◽  
Liquid Inoculant

Pumping equipment designed for seedbed inoculation of legumes with liquid inoculants was set up on a test bed in the laboratory. Experiments, in which liquid inoculant was circulated through the equipment, were conducted to determine the effect on inoculant viability of variables likely to be encountered when farmers used the equipment in the field. Provided that peat cultures of Rhizobium spp. were used to make liquid inoculant, neither pump type, operating pressure up to 173 kPa, water temperature up to 35�C, nor water impurity up to a level equivalent to 170 �S/cm conductivity seriously reduced inoculant populations during the first hour of treatment, although a significant decline in numbers occurred in three out of 16 experiments. When inoculant was exposed to the various treatments for long periods, a significant loss of viability occurred, in 7 out of 13 experiments, between 4-8 h. R. meliloti was least affected by treatment and R. leguminosarum most affected, but this may have been due to strain differences as much as to species differences. Liquid inoculants which were made from broth cultures lost viability very quickly. R.. meliloti liquid inoculant, prepared from a peat culture and introduced by spraying into a dry soil of neutral pH in the absence of any host plant, did not lose viability during a period of four weeks. The spray inoculation equipment was also used successfully in a field experiment to add water to the seedbed to aid in the germination of soybean seed sown into drying soil.

Pressure Transients in an Axial Piston Hydraulic Pump

1974 ◽  
Vol 188 (1) ◽  
pp. 189-199 ◽  
Author(s):  
B. O. Helgestad ◽  
K. Foster ◽  
F. K. Bannister
Keyword(s):  
Noise Reduction ◽  
Operating Conditions ◽  
Valve Plate ◽  
Hydraulic Pump ◽  
Noise Emission ◽  
Relief Valve ◽  
Pressure Transients ◽  
Theoretical Predictions ◽  
Axial Piston

A method is given for calculating pressure transients in an axial piston hydraulic pump. Some theoretical predictions are given of the effect of port timing and the effect of introducing restricting grooves at the ends of the kidney ports in the valve plate and suggestions are made of the effects of these parameters on noise emission; comparative measurements of noise are then quoted that support the general arguments. A parallel shot is recommended as the best compromise for the restrictor groove geometry to give good results over the widest range of operating conditions, including reverse rotation. Finally, mention is made of the use of a relief valve in the port plate for noise reduction.

scholarly journals Correlation between Reflection Coefficient, Dielectric Properties and Brix Level of Malaysian Oranges at Microwave Frequencies

2018 ◽  
Vol 10 (3) ◽  
pp. 853 ◽  
Author(s):  
Rafidah Rosman ◽  
Mohamad Ngasri Dimon ◽  
You Kok Yeow
Keyword(s):  
Dielectric Properties ◽  
Reflection Coefficient ◽  
Experimental Measurement ◽  
Operating Frequency ◽  
Test Bed ◽  
Microwave Frequencies ◽  
Microwave Technique ◽  
Set Up ◽  
The Relationship

This paper presents sweetness degree (°Brix) prediction of the Malaysian oranges using microwave technique. Experimental measurement using monopole sensor and reflectometer was done in order to correlate the relationship between measured reflection coefficient, <em>S</em><sub>11</sub>  of the orange and its sweetness level. Up to fifty orange samples were freshly plucked from local grower’s farm and tested. The unique design of the monopole sensor’s holder is made of nylon. The experiment test bed was set up based on the standard dimension of monopole sensor available in the market. The operating frequency is focusing on 2.2 GHz as it shows significant sensitivity for determining Malaysian local oranges sweetness level.

Intelligent Time-Stepping for Practical Numerical Simulation

2021 ◽  
Author(s):  
Soham Sheth ◽  
Francois McKee ◽  
Kieran Neylon ◽  
Ghazala Fazil
Keyword(s):  
Heuristic Method ◽  
Simulation Models ◽  
Model Complexity ◽  
Large Field ◽  
Optimal Time ◽  
Time Step ◽  
Non Linear ◽  
Set Up ◽  
Reservoir Simulator ◽  
Step Selection

Abstract We present a novel reservoir simulator time-step selection approach which uses machine-learning (ML) techniques to analyze the mathematical and physical state of the system and predict time-step sizes which are large while still being efficient to solve, thus making the simulation faster. An optimal time-step choice avoids wasted non-linear and linear equation set-up work when the time-step is too small and avoids highly non-linear systems that take many iterations to solve. Typical time-step selectors use a limited set of features to heuristically predict the size of the next time-step. While they have been effective for simple simulation models, as model complexity increases, there is an increasing need for robust data-driven time-step selection algorithms. We propose two workflows – static and dynamic – that use a diverse set of physical (e.g., well data) and mathematical (e.g., CFL) features to build a predictive ML model. This can be pre-trained or dynamically trained to generate an inference model. The trained model can also be reinforced as new data becomes available and efficiently used for transfer learning. We present the application of these workflows in a commercial reservoir simulator using distinct types of simulation model including black oil, compositional and thermal steam-assisted gravity drainage (SAGD). We have found that history-match and uncertainty/optimization studies benefit most from the static approach while the dynamic approach produces optimum step-sizes for prediction studies. We use a confidence monitor to manage the ML time-step selector at runtime. If the confidence level falls below a threshold, we switch to traditional heuristic method for that time-step. This avoids any degradation in the performance when the model features are outside the training space. Application to several complex cases, including a large field study, shows a significant speedup for single simulations and even better results for multiple simulations. We demonstrate that any simulation can take advantage of the stored state of the trained model and even augment it when new situations are encountered, so the system becomes more effective as it is exposed to more data.

A Fast and Effective Method for the Optimization of the Valve Plate of Swashplate Axial Piston Pumps

2021 ◽  
Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Kim Stelson ◽  
Adolfo Senatore
Keyword(s):  
Numerical Model ◽  
Dynamic Pressure ◽  
Valve Plate ◽  
Lumped Parameter Model ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Lumped Parameter ◽  
Pressure Ripple ◽  
Axial Piston

Abstract This research presents a lumped parameter numerical model aimed at designing and optimizing an axial piston pump. For the first time, it has been shown that a lumped parameter model can accurately model axial piston pump dynamics based on a comparison with CFD models and experimental results. Since the method is much more efficient than CFD, it can optimize the design. Both steady-state and dynamic behaviors have been analyzed. The model results have been compared with experimental data, showing a good capacity in predicting the pump performance, including pressure ripple. The swashplate dynamics have been investigated experimentally, measuring the dynamic pressure which controls the pump displacement; a comparison with the numerical model results confirmed the high accuracy. An optimization process has been conducted on the valve plate geometry to control fluid-born noise by flow ripple reduction. The NLPQL algorithm is used since it is suitable for this study. The objective function to minimize is the well-known function, the Non-Uniformity Grade, a parameter directly correlated with flow ripple. A prototype of the best design has been realized and tested, confirming a reduction in the pressure ripple. An endurance test was also conducted. As predicted from the numerical model, a significant reduction of cavitation erosion was observed.

Social Space in Simulation Models

2014 ◽  
pp. 200-219
Author(s):  
Davide Nunes ◽  
Luis Antunes
Keyword(s):  
Social Relations ◽  
Social Space ◽  
Opinion Dynamics ◽  
Simulation Models ◽  
Opinion Formation ◽  
Consensus Formation ◽  
Space Design ◽  
Network Topologies ◽  
Multiple Interaction ◽  
Set Up

In real world scenarios, the formation of consensus is a self-organisation process by which actors have to make a joint assessment about a target subject, be it a decision making problem or the formation of a collective opinion. In social simulation, models of opinion dynamics tackle the opinion formation phenomena. These models try to make an assessment, for instance, of the ideal conditions that lead an interacting group of agents to opinion consensus, polarisation or fragmentation. This chapter investigates the role of social relation structure in opinion dynamics and consensus formation. The authors present an agent-based model that defines social relations as multiple concomitant social networks and explore multiple interaction games in this structural set-up. They discuss the influence of complex social network topologies where actors interact in multiple distinct networks. The chapter builds on previous work about social space design with multiple social relations to determine the influence of such complex social structures in a process such as opinion formation.

Detecting Denial of Service Attacks on SIP Based Services and Proposing Solutions

2011 ◽  
pp. 145-167 ◽  
Author(s):  
Zoha Asgharian ◽  
Hassan Asgharian ◽  
Ahmad Akbari ◽  
Bijan Raahemi
Keyword(s):  
Denial Of Service ◽  
Denial Of Service Attacks ◽  
False Alarms ◽  
Test Bed ◽  
Multimedia Services ◽  
Detection Rates ◽  
Signaling Protocol ◽  
Detection Techniques ◽  
Set Up

One of the main goals of employing Next Generation Networks (NGN) is an integrated access to the multimedia services like Voice over IP (VoIP), and IPTV. The primary signaling protocol in these multimedia services is Session Initiation Protocol (SIP). This protocol, however, is vulnerable to attacks, which may impact the Quality of Service (QoS), which is an important feature in NGN. One of the most frequent attacks is Denial of Service (DoS) attack, which is generated easily, but its detection is not trivial. In this chapter, a framework is proposed to detect Denial of Service attacks and a few other forms of intrusions, and then we react accordingly. The proposed detection engine combines the specification- and anomaly-based intrusion detection techniques. The authors set up a test-bed and generate a labeled dataset. The traffic generated for the test-bed is composed of two types of SIP packets: attack and normal. They then record the detection rates and false alarms based on the labeled dataset. The experimental results demonstrate that the proposed approach can successfully detect intruders and limit their accesses. The results also confirm that the framework is scalable and robust.

Set-up and evaluation of a virtual test bed for simulating and comparing single- and mixed-mode ventilation strategies

2019 ◽  
Vol 151 ◽  
pp. 97-111
Author(s):  
B. Belmans ◽  
D. Aerts ◽  
S. Verbeke ◽  
A. Audenaert ◽  
F. Descamps
Keyword(s):  
Mixed Mode ◽  
Test Bed ◽  
Virtual Test ◽  
Virtual Test Bed ◽  
Ventilation Strategies ◽  
Set Up

scholarly journals Repeatability of High-Pressure Measurement in a Diesel Engine Test Bed

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3478 ◽  
Author(s):  
Tomasz Skrzek ◽  
Mirosław Rucki ◽  
Krzysztof Górski ◽  
Jonas Matijošius ◽  
Dalibor Barta ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Pressure Measurement ◽  
Ignition Process ◽  
Engine Test ◽  
Cylinder Pressure ◽  
Test Bed ◽  
Working Cycle ◽  
Crank Angle ◽  
Maximal Pressure ◽  
Measured Pressure

This paper addresses the issue of metrological accuracy of instantaneous in-cylinder pressure measurement in a diesel engine test bed. In studies, the central unit has been the single-cylinder AVL 5402 engine. The pressure measurement was performed with a sensor designed for thermodynamic analysis, and the results were related to the crank angle, where two rotations corresponding to the four-stroke working cycle were denoted as angles between −360° and +360°. The novelty of this paper is the proposition of how to perform a type A uncertainty estimation of the in-cylinder pressure measurement and to assess its repeatability. It was demonstrated that repeatability of the measurement during the ignition process was difficult to estimate because of the phenomena that cannot ensure the repeatability conditions. To solve the problem, two methods were proposed. In one method, the pressure was measured in the subsequent cycles immediately after the ignition was turned off, and in another method, the engine was driven by a starter. The latter method provided maximal pressure values much lower than during usual tests. The obtained repeatability of measured pressure was %EV = 0.4%, which proved high capability of the evaluated measurement system.

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