scholarly journals Analysis of Factors Influencing Vibration Suppression of Spray Boom-Air Suspension for Medium and Small-Scale High-Clearance Sprayers

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6753
Author(s):  
Wei Qiu ◽  
Xinyue Yao ◽  
Yue Zhu ◽  
Hao Sun ◽  
Liangfu Zhou ◽  
...  
Keyword(s):  
Field Experiments ◽  
Vibration Suppression ◽  
Damping Coefficient ◽  
Bench Test ◽  
Homogeneous Distribution ◽  
Small Scale ◽  
Air Spring ◽  
Air Suspension ◽  
Air Chamber ◽  
High Clearance

Medium and small-scale high-clearance sprayers are widely applied in medium and small-scale farms. Owing to power and load limitations, it is difficult to manage the complex system for suppressing spray boom vibration. This study was conducted to design a spray boom-air suspension system suitable for medium and small-size high-clearance sprayers by combining spray boom vibration suppression and the characteristics of air spring charging/discharging. Thus, this study aims to address the non-homogeneous distribution of spray triggered by the spray boom vibrations in medium and small high-clearance sprayers. The effects of different elastic elements on the vibration suppression effect of the spray boom were compared. According to the bench test, the dynamic response results of the spray boom under transient and sinusoidal excitations indicate that air spring is more conducive to vibration suppression than coil spring. The results obtained from the field experiments indicate that under the low solid soil condition, the spray boom air suspension should match a small additional air chamber with a volume of approximately 0.6 L, and the damping coefficient of the damper should be approximately 1792 N·s/m. In the case of the high firm soil, the spray boom air suspension should match a large additional air chamber with a volume of approximately 3.6 L, while the damping coefficient of the damper should be set to approximately 1316 N·s/m. The soil with low moisture content and high firmness are unfavorable to the vibration suppression of the spray boom. This study provides a reference for enhancing the vibration suppression of the spray boom-air suspension and improving the spray uniformity of the sprayer.

Single-Bagged Air Spring’s Parameter Calculation

2001 ◽  
Author(s):  
Jingjun Lou ◽  
Shijian Zhu ◽  
Weijian Qian ◽  
Lin He
Keyword(s):  
Dynamic Model ◽  
Natural Frequency ◽  
State Equation ◽  
Damping Coefficient ◽  
Air Spring ◽  
Factors Affecting ◽  
Parameter Calculation ◽  
Air Chamber

Abstract This paper sets up a dynamic model of a single-bagged air spring with an auxiliary air chamber on the basis of the polytrope process state equation. The calculation formulas for stiffness and natural frequency are derived. Factors affecting damping coefficient and natural frequency are analyzed.

The Study on Control and Riding Comfort of Air Suspension

2014 ◽  
Vol 1006-1007 ◽  
pp. 304-307
Author(s):  
Qi Yao Yang ◽  
Jian Zhong Zhang ◽  
Yu Ping Ma ◽  
Yue Bo Wu ◽  
Wen Na Zhang
Keyword(s):  
Pid Control ◽  
Pid Controller ◽  
Control Algorithm ◽  
Bench Test ◽  
Test Results ◽  
Vehicle Model ◽  
Air Spring ◽  
Air Suspension ◽  
Target Values ◽  
Electronically Controlled Air Suspension

In order to improve vehicles comfort, electronically controlled air suspension is taken as study object. We designed the PID controller, which can regulates stiffness and height of air spring. Taking stiffness of air suspension as control variables, and the acceleration of the sprungmass as target values, one-quarter vehicle model of air suspension for bench test is established, then PID control system was tested on the bench.The bench test results show that the PID control algorithm can improve vehicle ride performance.

scholarly journals Applications of Chemically Modified Clay Minerals and Clays to Water Purification and Slow Release Formulations of Herbicides

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Tomas Undabeytia ◽  
Uri Shuali ◽  
Shlomo Nir ◽  
Baruch Rubin
Keyword(s):  
Clay Minerals ◽  
Field Experiments ◽  
Slow Release ◽  
Freeze Fracture ◽  
Nano Particles ◽  
Organic Cations ◽  
Small Scale ◽  
High Exposure ◽  
Model Calculations ◽  
Slow Release Formulations

This review deals with modification of montmorillonite and other clay-minerals and clays by interacting them with organic cations, for producing slow release formulations of herbicides, and efficient removal of pollutants from water by filtration. Elaboration is on incorporating initially the organic cations in micelles and liposomes, then producing complexes denoted micelle- or liposome-clay nano-particles. The material characteristics (XRD, Freeze-fracture electron microscopy, adsorption) of the micelle– or liposome–clay complexes are different from those of a complex of the same composition (organo-clay), which is formed by interaction of monomers of the surfactant with the clay-mineral, or clay. The resulting complexes have a large surface area per weight; they include large hydrophobic parts and (in many cases) have excess of a positive charge. The organo-clays formed by preadsorbing organic cations with long alkyl chains were also addressed for adsorption and slow release of herbicides. Another examined approach includes “adsorptive” clays modified by small quaternary cations, in which the adsorbed organic cation may open the clay layers, and consequently yield a high exposure of the siloxane surface for adsorption of organic compounds. Small scale and field experiments demonstrated that slow release formulations of herbicides prepared by the new complexes enabled reduced contamination of ground water due to leaching, and exhibited enhanced herbicidal activity. Pollutants removed efficiently from water by the new complexes include (i) hydrophobic and anionic organic molecules, such as herbicides, dissolved organic matter; pharmaceuticals, such as antibiotics and non-steroidal drugs; (ii) inorganic anions, e.g., perchlorate and (iii) microorganisms, such as bacteria, including cyanobacteria (and their toxins). Model calculations of adsorption and kinetics of filtration, and estimation of capacities accompany the survey of results and their discussion.

scholarly journals Analysis of Vertical Stiffness of Air Spring Based on Finite Element Method

2018 ◽  
Vol 153 ◽  
pp. 06006
Author(s):  
Jiatong Ye ◽  
Hua Huang ◽  
Chenchen He ◽  
Guangyuan Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Element Model ◽  
Simulation Method ◽  
Bench Test ◽  
Air Spring ◽  
Vertical Stiffness ◽  
Element Simulation ◽  
Element Method

In this paper, a finite element model of membrane air spring in the vehicle is established, and its vertical stiffness characteristics under a certain inflation pressure are analysed. The result of finite element simulation method is compared with the result of the air spring bench test. The accuracy and reliability of the finite element simulation method in nonlinear analysis of air spring system are verified. In addition, according to the finite element method, the influence of the installation of the air spring limit sleeve on its stiffness is verified.

Active vibration suppression of elastic blade structure: Using a novel magnetorheological layer patch

2018 ◽  
Vol 29 (19) ◽  
pp. 3792-3803 ◽  
Author(s):  
Fevzi Cakmak Bolat ◽  
Selim Sivrioglu
Keyword(s):  
Wind Turbine ◽  
Vibration Suppression ◽  
State Space Model ◽  
Interaction Model ◽  
Parametric Uncertainty ◽  
Small Scale ◽  
Aerodynamic Load ◽  
Active Vibration Suppression ◽  
Active Vibration ◽  
Blade Element

This research study proposes a new active control structure to suppress vibrations of a small-scale wind turbine blade with attached magnetorheological fluid patch actuated by an electromagnet. The blade structure is manufactured by an aluminum extrusion machine considering the airfoil data of SH3055 which is designed for use on a small wind turbine. An interaction model between the magnetorheological patch and the electromagnetic actuator is derived and a force characterization is realized. A norm-based multiobjective H2/ H∞ controller is designed using the state-space model of the elastic blade element. The H2/ H∞ controller is experimentally implemented under the steady-state aerodynamic load conditions. The results of experiments show that the magnetorheological layer patch is effective for suppressing vibrations of the blade structure and robust against parametric uncertainty.

Progress towards small-scale field trials of coastal enhanced weathering of olivine

2021 ◽  
Author(s):  
Stephen Romaniello ◽  
Shanee Stopnitzky ◽  
Tom Green ◽  
Francesc Montserrat ◽  
Eric Matzner ◽  
...  
Keyword(s):  
Real World ◽  
Field Experiments ◽  
Ecological Impact ◽  
Field Trials ◽  
Research Strategy ◽  
Unintended Consequences ◽  
Ecological Impacts ◽  
Small Scale ◽  
Climate Mitigation ◽  
Stage Of Development

<p>Slow progress towards achieving global greenhouse gas emissions targets significantly increases the likelihood that future climate efforts may require not only emissions cuts but also direct climate mitigation via negative emissions technologies (IPCC AR5). Currently, such technologies exist at only a nascent stage of development, with significant uncertainties regarding their feasibility, cost, and potential unintended consequences and/or co-benefits.</p><p>Coastal enhanced weathering of olivine (CEWO) has been suggested as one potential pathway for achieving net negative CO<sub>2</sub> emissions at scale. CEWO involves the mining of olivine-rich ultramafic rocks (such as dunite) for incorporation during beach augmentation and restoration work. While grinding this rock into increasingly fine particle sizes is essential for increasing its surface area and reactivity, this step is also costly and energetically expensive. CEWO attempts to minimize this cost and energy penalty by relying on wave and tidal action to provide ongoing physical weathering of olivine grains once distributed on beaches. Laboratory experiments and carbon emissions assessments of CEWO suggest that these approaches may be technically feasible and carbon negative, but significant uncertainties remain regarding the real-world kinetics of coastal olivine dissolution. Furthermore, concerns about the fate and ecological impact of nickel (Ni) and chromium (Cr)—potentially toxic trace metals found in olivine—require careful evaluation.</p><p>In 2019, Project Vesta was established as a nonprofit, philanthropically funded effort to evaluate the technical feasibility and ecological impacts of CEWO through a dedicated research program ultimately culminating in small-scale, real-world field trials of CEWO. This presentation will provide an overview and discussion of our overall research strategy, share insights from interim modeling and mesocosm experiments designed to ensure the practicality and safety of future field experiments, and explain our approach for ensuring transparent, responsible, and ethical research oversight and governance.</p>

Non-Linear Space-Time Evolution of Wave Groups With a High Crest

2003 ◽  
Author(s):  
Felice Arena ◽  
Francesco Fedele
Keyword(s):  
Time Evolution ◽  
Field Experiments ◽  
Surface Displacement ◽  
Fixed Time ◽  
Space Time ◽  
Second Order ◽  
Small Scale ◽  
Free Surface Displacement ◽  
Non Linear ◽  
Space Time Evolution

The theory of quasi-determinism, for the mechanics of linear three-dimensional waves, was obtained by Boccotti in the eighties. The first formulation of the theory deals with the largest crest amplitude; the second formulation deals with the largest wave height. The theory was verified in the nineties with some small-scale field experiments. In this paper the first formulation of Boccotti’s theory, valid for the space-time domain, is extended to the second order. The analytical expressions of the non-linear free surface displacement and velocity potential are obtained. Therefore the space-time evolution of a wave group, to the second-order in a Stokes expansion, when a very large crest occurs at a fixed time and location, is investigated. Finally the second-order probability of exceedance of the crest amplitude is obtained, as a function of two deterministic parameters.

Seismic Performance of Vibration Control Device That Generates Power

2009 ◽  
Author(s):  
Taichi Matsuoka ◽  
Katsuaki Sunakoda ◽  
Kazuhiko Hiramoto ◽  
Issei Yamazaki ◽  
Akira Fukukita ◽  
...  
Keyword(s):  
Vibration Control ◽  
Earthquake Engineering ◽  
Vibration Suppression ◽  
Experimental Testing ◽  
Control Device ◽  
Shaking Table ◽  
Ball Screw ◽  
Scale Model ◽  
Small Scale ◽  
Wide Range

In a previous paper the authors proposed a semi-active vibration control device (VCD) that generates power. The device utilizes a ball screw, and has inertial and damping forces. The damping coefficient is adjusted by altering resistance at the terminal of the power generator. A small-scale VCD was manufactured for experimental testing. Frequency responses of a small-scale spring mass structure were measured in order to confirm the effects of vibration suppression within a wide range of frequencies. In this paper, as the next step, vibration tests using a benchmark structure with an installed VCD that has a 30 kN capacity are carried out at the National Center for Research on Earthquake Engineering (NCREE) in Taiwan. The benchmark structure has three stories with a 3 m height and a mass of 6 tons at each floor level for a total height and weight of 9 m and 18 tons, respectively. The VCDs are installed between adjacent floors with steel chevron braces. A simple control law that is based on a minimized Lyapunov function and employs bang-bang operation is used as a variable current controller instead of the modifying the resistance level of the VCD. Scaled earthquake motions including the Imperial Valley El Centro north-south component that is normalized to be a peak level of 0.5 m/s2, are applied to the base of the steel framed structure in the horizontal direction by a shaking table. Experimental responses of each floor for the uncontrolled and controlled cases are compared with analytical responses, and effects of vibration suppression for the large-scale model are discussed quantitatively.

scholarly journals Mission-driven research for stratospheric aerosol geoengineering

2019 ◽  
Vol 116 (4) ◽  
pp. 1089-1094 ◽  
Author(s):  
Douglas G. MacMartin ◽  
Ben Kravitz
Keyword(s):  
Radiative Forcing ◽  
Field Experiments ◽  
Research Effort ◽  
Science Research ◽  
Global Scale ◽  
Stratospheric Aerosol ◽  
Small Scale ◽  
Exploratory Research ◽  
Climate Risks ◽  
Research Activities

The last decade has seen broad exploratory research into stratospheric aerosol (SA) geoengineering, motivated by concern that reducing greenhouse gas emissions may be insufficient to avoid significant impacts from climate change. Based on this research, it is plausible that a limited deployment of SA geoengineering, provided it is used in addition to cutting emissions, could reduce many climate risks for most people. However, “plausible” is an insufficient basis on which to support future decisions. Developing the necessary knowledge requires a transition toward mission-driven research that has the explicit goal of supporting informed decisions. We highlight two important observations that follow from considering such a comprehensive, prioritized natural-science research effort. First, while field experiments may eventually be needed to reduce some of the uncertainties, we expect that the next phase of research will continue to be primarily model-based, with one outcome being to assess and prioritize which uncertainties need to be reduced (and, as a corollary, which field experiments can reduce those uncertainties). Second, we anticipate a clear separation in scale and character between small-scale experimental research to resolve specific process uncertainties and global-scale activities. We argue that the latter, even if the radiative forcing is negligible, should more appropriately be considered after a decision regarding whether and how to deploy SA geoengineering, rather than within the scope of “research” activities.

Sign in / Sign up

Export Citation Format

Share Document