Modeling and Experiments of an Annular Multi-Channel Magnetorheological Valve

With the increasing number of cars, the demand for vehicle maintenance lifts is also increasing. The hydraulic valve is one of its core components, but there are problems with it such as inaccurate positioning and failure. In order to improve the service performance of vehicle maintenance elevators, a novel annular multi-channel magnetorheological (MR) valve structure was creatively proposed based on intelligent material MR fluid (MRF), and its magnetic circuit was designed. The influence of current, damping gap and coil turns on the pressure drop performance of the annular multi-channel MR valve was numerically studied and compared with ordinary type magnetorheological valve pressure drop performance through contrast and analysis. The influence of different loads and currents on the pressure drop performance of annular multi-channel magnetorheological valve was verified by experiments, and the reliability of numerical analysis results was verified. The results show that the single winding excitation coil is 321 to meet the demand. The pressure drop performance of the annular multi-channel magnetorheological valve is 5.6 times that of the ordinary magnetorheological valve. The load has little influence on the regulating range and performance of pressure drop of the MR valve. Compared with the common type, the pressure drop performance of the annular multi-channel MR Valve is improved by 3.7 times, which is basically consistent with the simulation results.

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Optimal Design and Performance Analysis of Radial MR Valve with Single Excitation Coil

Actuators ◽

10.3390/act10020034 ◽

2021 ◽

Vol 10 (2) ◽

pp. 34

Author(s):

Guoliang Hu ◽

Feng Zhou ◽

Lifan Yu

Keyword(s):

Pressure Drop ◽

Magnetic Flux ◽

Internal Structure ◽

Total Pressure ◽

Damping Force ◽

Flux Lines ◽

Total Pressure Drop ◽

Excitation Coil ◽

Static Performance ◽

And Performance

The main issue addressed in this paper involves the magnetorheological (MR) valve increasing the pressure drop by changing the internal structure, which leads to the increase of dimension sizes and the easy blocking of the internal channel. Optimizing the design of the traditional radial MR valve without changing the internal structure and whole dimension size is indispensable. Firstly, a radial MR valve with single excitation coil was proposed. The mathematical models of the field-dependent pressure drop and viscosity pressure drop in fluid flow channels were deduced, and the calculation formula of pressure drop was also established. Then, ANSYS software was used to simulate and analyze the distributions of the magnetic flux lines and magnetic flux densities of the proposed radial MR valve. Subsequently, the radial MR valve was simulated and analyzed by using the ANSYS first-order and zero-order simulation tools. In addition, the experimental test bench of the proposed MR valve was setup, the static performance of pressure drop was tested, and the change of pressure drop of the optimal radial MR valve under different loads was studied, furthermore, the response time with current of the initial and optimal radial MR valve were also investigated. Finally, the dynamic performances of the optimal radial MR valve controlled cylinder system under different currents, frequencies and amplitudes were tested, respectively. The experimental results indicate that the total pressure drop of the initial valve is 1.842 MPa when the applied current is 1.8 A, and the total pressure drop of the optimal valve is 2.58 MPa, the increase is 40.07%. Meanwhile, the maximum damping force of the optimal radial MR valve controlled cylinder system can reach about 3.6 kN at the current of 1.25 A, which shows a better optimization effect of the optimal radial MR valve.

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Predicting Hydraulic Valve Pressure Drop Using CFD

10.4271/2005-01-3635 ◽

2005 ◽

Cited By ~ 6

Author(s):

Roger Yang

Keyword(s):

Pressure Drop ◽

Hydraulic Valve ◽

Valve Pressure

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The (Im)purity Levels of Communal Meals within the Qumran Movement

Journal of Ancient Judaism ◽

10.30965/21967954-00701008 ◽

2016 ◽

Vol 7 (1) ◽

pp. 102-122

Author(s):

Cecilia Wassén

Keyword(s):

Careful Study ◽

Ordinary Type ◽

The Common ◽

The Temple

Scholars usually take for granted that the sectarian members of the Qumran movement ate their common meals in full purity at a level that is often compared to that of the priests serving in the temple. This assumption rests on the interpretation of hatohorah, “the purity,” as pertaining to common meals. But a careful study of a range of texts, including the important Tohorot A, leads to a more nuanced picture. Accordingly, it is important to distinguish between the common, everyday meals of the movement and the special meals. Whereas a mild level of impurity of the participants was accepted at the ordinary type of communal meals, special meals required purity. Even at these pure meals, there were variations concerning the required level of purity depending on the occasion.

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Development and performance study of a natural silk fiber facial mask paper

Journal of Engineered Fibers and Fabrics ◽

10.1177/1558925020975756 ◽

2020 ◽

Vol 15 ◽

pp. 155892502097575

Author(s):

Huiling Wang ◽

Bin Zhou

Keyword(s):

Silk Fiber ◽

Entrainment Rate ◽

Performance Study ◽

Wet Strength ◽

Facial Mask ◽

Antibacterial Performance ◽

Lower Elongation ◽

The Common ◽

And Performance ◽

Acid Structure

Facial masks are beauty products which composed of a facial mask paper and beauty solution. Silk contains the amino acid structure closest to the human skin, and has the skin-friendly, cosmetic and antibacterial functions, but the common method for making nonwoven facial mask paper is not suitable for silk. In this paper, the silkworm’s spinning path is intervened manually to obtain a smart silk facial mask paper (SMC) of controllable thickness, so that the sericin on the silk fiber is well preserved. In the experiment where the SMC is compared with the nonwoven 384-cuprammonium rayon facial mask paper (CRMC) which is the most widely used in the market, it is found that the ways of forming the two facial mask paper are completely different, and therefore the morphologies under SEM are obviously different. The thickness of the SMC is 0.183 mm and the areal weight of it is 38.0 g/m2. It is very close to the CRMC (0.187 mm, 38.4 g/m2). The porosity of the SMC is 84.0%, which is slightly lower than that of the CRMC (86.3%), but its pores are well distributed. Compared with the CRMC, the smart SMC has higher dry and wet strength, lower elongation, slightly lower air permeability and liquid entrainment rate, and better antibacterial performance.

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Flow Coefficient Evaluation of Poppet Valves Used in Reciprocating Compressors for LDPE

Volume 5: High Pressure Technology; Nondestructive Evaluation Division; Student Paper Competition ◽

10.1115/pvp2008-61286 ◽

2008 ◽

Author(s):

Enzo Giacomelli ◽

Massimo Schiavone ◽

Fabio Manfrone ◽

Andrea Raggi

Keyword(s):

Pressure Drop ◽

Time Pressure ◽

Experimental Tests ◽

Operating Conditions ◽

Flow Coefficient ◽

Operating Life ◽

High Fatigue ◽

Strongly Connected ◽

And Performance ◽

Poppet Valves

Poppet valves have been used for a long time for very high pressure reciprocating compressors, as for example in the case of Low Density Polyethylene. These applications are very critical because the final pressure can reach 350 MPa and the evaluation of the performance of the machines is strongly connected to the proper operation and performance of the valve itself. The arrangement of cylinders requires generally a certain compactness of valve to withstand high fatigue stresses, but at the same time pressure drop and operating life are very important. In recent years the reliability of the machines has been improving over and over and the customers’ needs are very stringent. Therefore the use of poppet valves has been extended to other cases. In general the mentioned applications are heavy duty services and the simulation of the valves require some coefficients to be used in the differential equations, able to describe the movement of plate/disk or poppet and the flow and related pressure drop through the valves. Such coefficients are often determined in an experimental way in order to have a simulation closer to the real operating conditions. For the flow coefficients it is also possible today to use theoretical programs capable of determining the needed values in a quick and economical way. Some investigations have been carried out to determine the values for certain geometries of poppet valves. The results of the theory have been compared with some experimental tests. The good agreement between the various methods indicates the most suitable procedure to be applied in order to have reliable data. The advantage is evident as the time necessary for the theoretical procedure is faster and less expensive. This is of significant importance at the time of the design and also in case of a need to provide timely technical support for the operating behavior of the valves. Particularly for LDPE, the optimization of all the parameters is strongly necessary. The fatigue stresses of cylinder heads and valve bodies have to match in fact with gas passage turbulence and pressure drop, added to the mechanical behavior of the poppet valve components.

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When Bilingualism is the Common Factor: Switch Reference at the Junction of Competence and Performance in Both Second Language and Heritage Language Performance

Journal of Language Contact ◽

10.1163/19552629-01103008 ◽

2018 ◽

Vol 11 (3) ◽

pp. 590-616 ◽

Cited By ~ 1

Author(s):

Tiffany Judy ◽

Michael T. Putnam ◽

Jason Rothman

Keyword(s):

Second Language ◽

Adult Learners ◽

Heritage Language ◽

Common Factor ◽

Language Performance ◽

Subject Pronouns ◽

Different Populations ◽

The Common ◽

And Performance ◽

Heritage Language Speakers

In this paper we take a closer look at the oft-touted divide between heritage language speakers and adult second language (L2) learners. Here, we explore whether some properties of language may display general effects across different populations of bilinguals, explaining, at least partially, why these two groups show some common differences when compared with monolinguals. To test this hypothesis, we adduce data from two unique populations of bilinguals: a moribund variety of heritage German spoken in southwestern Kansas (Moundridge Schweitzer German) and L2 adult learners of Spanish. Empirically, we investigate whether the confound of switch reference adds an additional cognitive burden to these bilinguals in licensing object control predicates in the former and referential subject pronouns in the latter. Our preliminary findings support the view that overarching concepts such as incomplete acquisition cannot capture the variability observed in these populations, thus further supporting approaches that interpret findings such as these to be the result of specific variables.

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Regenerated Marine Gas Turbines: Part II — Regenerator Technology and Heat Exchanger Sizing

Volume 2: Aircraft Engine; Marine; Microturbines and Small Turbomachinery ◽

10.1115/82-gt-314 ◽

1982 ◽

Cited By ~ 1

Author(s):

J. W. Watts ◽

T. L. Bowen

Keyword(s):

Heat Exchanger ◽

Pressure Drop ◽

Performance Improvement ◽

Gas Turbines ◽

Performance Parameters ◽

Next Generation ◽

Plate Spacing ◽

Naval Ship ◽

And Performance ◽

Regenerative Cycle

Analytical studies are currently being conducted by the David Taylor Naval Ship R&D Center to assess the suitability of regenerative-cycle and intercooled, regenerative-cycle gas turbines for naval applications. This paper is the second part of a two-part paper which discusses results of initial investigations to identify attractive engine concepts based on existing turbomachinery and to consider the regenerator technology required to develop these engine concepts. Part I of the paper analyzed existing and next generation engines for performance improvement. Part II includes: definitions of performance parameters such as effectiveness and pressure drop, a discussion of regenerator types, and comments on regenerator materials, life, maintenance, and fouling. Tradeoffs between size, weight, and performance of plate-fin recuperators are examined using two of the hypothetical engines from Part I as examples. Results are compared for several different recuperator matrices to illustrate the effects of air-side and gas-side fin density and plate spacing on size, weight, and performance.

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Poetics

The Year s Work in Critical and Cultural Theory ◽

10.1093/ywcct/mbab013 ◽

2021 ◽

Author(s):

Sarah Dowling

Keyword(s):

Common Sense ◽

Art Forms ◽

Performance Texts ◽

The Common ◽

The Senses ◽

And Performance

Abstract This review examines three books published in the field of poetics in 2020: Candice Amich’s Precarious Forms: Performing Utopia in the Neoliberal Americas; Ren Ellis Neyra’s The Cry of the Senses: Listening to Latinx and Caribbean Poetics; and Anthony Reed’s Soundworks: Race, Sound, and Poetry in Production. I show that these three books, which discuss poetry in connection with other art forms, each call for a reordering of the senses through which we perceive and analyze poetry (and other texts). While Ellis Neyra advocates multisensorial listening and Reed calls for a mode of listening attentive to what remains unnamed within current perceptual and political schema, Amich shows the importance of paying attention to the embodied rhythms and tactility of poetry and performance texts. For all three authors, these alternatives to individualized, detached, and indeed deadened linguistic contemplation proffer strategies for remaking not only common sense, but the common itself. The chapter is structured under the following headings: 1. Introduction; 2. Poetics; 3. Sensoria; 4. Politics.

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Mental health and addictions policy priorities and performance measurement frameworks

Healthcare Management Forum ◽

10.1177/0840470418810273 ◽

2019 ◽

Vol 32 (2) ◽

pp. 105-112

Author(s):

Frank Sirotich ◽

Carol E. Adair ◽

Janet Durbin ◽

Elizabeth Lin ◽

Christopher Canning

Keyword(s):

Mental Health ◽

Performance Measurement ◽

Future Development ◽

Measurement Framework ◽

Starting Point ◽

The Future ◽

The Common ◽

Performance Domains ◽

And Performance ◽

Measurement Practices

To inform the future development of a pan-Canadian Mental Health and Addictions (MHA) performance measurement framework, we undertook a review and comparison of current provincial/territorial MHA policies and performance measurement frameworks. Most did not have performance measurement approaches that were explicitly linked to policy actions but eleven acknowledged the importance of performance measurement. Among the provinces with a framework, there were few performance domains in common. The common policy priorities and areas of convergence in current performance measurement practices may provide a useful starting point for the development of a pan-Canadian MHA performance measurement framework.

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