Accurate calculations of working chamber volume constructed from involute of variable radii circle with double arcs modification in a scroll type compressor

2021 ◽  
pp. 095440892110136
Author(s):  
Jianan Ding ◽  
Xiangji Yue ◽  
Yingli Zhang ◽  
Dechun Ba
Keyword(s):  
Mathematical Modeling ◽  
Volume Ratio ◽  
Polytropic Index ◽  
Initial Radius ◽  
Working Chamber ◽  
Chamber Volume ◽  
Base Circle

A mathematical modeling of working chamber volume, constructed from the involute of variable radii circle with double arcs modification, is established in this study. The formulations of working chamber volume which is consisted of the involute of variable radii circle and modified by double arcs at center profiles are accurately deduced, and the orbiting angle of scroll at every moment has a corresponding working chamber volume. The effect of parameters on the working chamber volume is investigated. The different values of initial radius of base circle, starting involute angle, corrected increment, polytropic index and modified angle will change the working chamber volume. Furthermore, the effect of parameters on suction volume and volume ratio has been considered in this study, and the design schemes to obtain the highest volume radio are also studied. These results can be used to provide general implications in calculation of working chamber volume constructed from other type involutes and modifications.

scholarly journals RESEARCH OF VIBRATION MACHINES DYNAMICS FOR PRODUCT SURFACES PROCESSING BY MATHEMATICAL MODELING

2020 ◽  
pp. 35-43
Author(s):  
Volodymyr Topilnytskyy ◽  
Yaroslav Kusyi ◽  
Dariya Rebot
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Surface Treatment ◽  
Lagrange Equation ◽  
The Body ◽  
Technological Problem ◽  
Surface Processing ◽  
Approximate Methods ◽  
Vibration Machine ◽  
Working Chamber

The article describes the methodology for the study of the dynamics of vibrating machines for surface processing of products by mathematical modeling, which is presented in four main stages. The first stage: analysis of classes of vibrating machines for surface treatment of products, choice of basic for solving the technological problem, project of a unified calculation scheme of the machine. The second stage: development of a nonlinear mathematical model for describing the dynamics of the vibration machine working body and its filling, development of elements of automated calculations of the machine. The third stage: the study of the influence of the parameters of the vibrating machine, product sets and tools (with their various combinations) on the factors of the intensity of products surface processing. The fourth stage: recommendations for choosing vibrating machine parameters and machining bodies that will maximize the processing performance of products with the selected intensity criterion. A mathematical model for describing the motion of a vibrating machine for surface treatment of articles by a set of unrelated bodies of small size is created. It has two unbalance units that generate oscillations of its working body and a spring suspension-mounting of the working chamber (container). The model is parametric and nonlinear, incorporating key dynamic, kinematic and geometric parameters of the vibrating machine in symbolic format. It is constructed by: descriptions of the plane-parallel movement of the mechanical system, the rotational motion of the material point and the body; second-order Lagrange equation; asymptotic (approximate) methods of nonlinear mechanics. With the help of the model it is possible: to describe the oscillatory movement of the working chamber (container) of the vibrating machine; to study the influence of the machine parameters on the efficiency of performance of the set technological task, the conditions of occurrence of non-stationary modes of operation of the vibrating machine and the ways of their regulation.

scholarly journals Experiences from operation of different expansion devices for application in domestic micro CHP

2010 ◽  
Vol 31 (4) ◽  
pp. 3-13 ◽  
Author(s):  
Dariusz Mikielewicsz ◽  
Jarosław Mikielewicz ◽  
Jan Wajs
Keyword(s):  
Electricity Grid ◽  
Working Chamber ◽  
Chamber Volume ◽  
Scroll Expander

Experiences from operation of different expansion devices for application in domestic micro CHPIn the paper presented are experiences from operation of three different expansion devices for possible implementation in the domestic micro CHP. These were the modified scroll expander and two designs based on the variable working chamber volume pneumatic devices. Experiments showed the superiority of both "pneumatic devices" over the scroll expander, indicating the possible internal efficiencies in the range of 61 82Such efficiencies are very attractive, especially at the higher end of that range. The volume of these devices is much smaller than the scroll expander which makes it again more suitable for a domestic micro CHP. Small rotational velocities enable to conclude that connection to electricity grid will also be simpler in the case of "pneumatic devices". The "pneumatic devices" under scrutiny here could be an alternative to the typical vapour turbine in the ORC cycle, which is in the process of development at the IFFM.

scholarly journals Physical and mathematical modeling of the moving the raw cotton between directing wall and area ginning seeds

2021 ◽  
Vol 2131 (3) ◽  
pp. 032056
Author(s):  
M Ahmedov ◽  
M Shoraxmedova ◽  
T Tuychiev ◽  
D Tashpulatov ◽  
I Cherunova
Keyword(s):  
Mathematical Modeling ◽  
Cotton Fiber ◽  
Quantitative Estimation ◽  
Experimental Studies ◽  
Raw Material ◽  
Direct Impact ◽  
Actual Problem ◽  
Working Chamber ◽  
Qualitative And Quantitative ◽  
Physical And Mathematical Modeling

Abstract In article are brought algorithm and results brought numerically-experimental studies on qualitative and quantitative estimation of the law of the moving the raw cotton from directing walls outgoing between spiked-drum and netlike surface feeder aside worker of the camera ginning machines. It is known that the uniform supply of raw cotton to the ginning process has a direct impact on the efficiency of the ginning process. In the process of ginning, the cotton is cleaned on the surface of the pile drum and net of the supplier, and the crushed gin comes to the working chamber through the gin. As a result of the rotation of the saw cylinder in the working chamber, the cotton fiber is suspended and the rotation is started. As a result of the circular motion of the raw cotton, a raw material roller is formed. In this process, the actual problem is to ensure that the raw cotton consists of small pieces and is uniform in time and width of the equipment. The Comparison got given on calculation shows that increase the corner will bring about increase the growing forming displacement. Increase of this corner will bring the leaflet of the raw cotton about increase of length free moving.

Combustion modelling of turbulent jet ignition in a divided combustion chamber

2021 ◽  
pp. 146808742110371
Author(s):  
Mattia Olcuire ◽  
Clara Iacovano ◽  
Alessandro d’Adamo ◽  
Sebastiano Breda ◽  
Tommaso Lucchini ◽  
...  
Keyword(s):  
Volume Ratio ◽  
Turbulent Jets ◽  
Combustion Regime ◽  
Nozzle Diameter ◽  
Turbulent Jet ◽  
Main Chamber ◽  
Lean Burn ◽  
Jet Flame ◽  
Chamber Volume ◽  
Combustion Modelling

Turbulent jet ignition is seen as one of the most promising strategies to achieve stable lean-burn operation in modern spark-ignition engines thanks to its ability to promote rapid combustion. A nearly stoichiometric mixture is ignited in a small-volume pre-chamber, following which multiple hot turbulent jets are discharged in the main chamber to initiate combustion. In the present work, a detailed computational investigation on the turbulent combustion regime of premixed rich propane/air mixture in a quiescent divided chamber vessel is carried out, to study the characteristics of the jet flame without the uncertainties in mixing and turbulent conditions typical of real-engine operations. In particular, the paper investigates the dependency of flame propagation on nozzle diameter (4, 6, 8, 12 and 14 mm) and pre-chamber/main-chamber volume ratio (10% and 20%); CFD results are compared to the experimental outcomes. Results show that the combustion regime in the quiescent pre-chamber follows a well-stirred reaction mode, rendering the limitation in using conventional flamelet combustion models. Furthermore, due to the very high turbulence levels generated by the outflowing reacting jets, also the main chamber combustion develops in a well-stirred reactor type, confirming the need for a kinetics-based approach to combustion modelling. However, the picture is complicated by thickened flamelet conditions possibly being verified for some geometrical variations (nozzle diameter and pre-chamber volume). The results show a general good alignment with the experimental data in terms of both jet phasing and combustion duration, offering a renewed guideline for combustion simulations under quiescent and low Damköhler number conditions.

Abstract 1018: Cardiac Progenitor Cells and Biotinylated IGF-1 Nanofibers Improve Endogenous and Exogenous Myocardial Regeneration after Infarction

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Yu Misao ◽  
Michael E Davis ◽  
Vincent E Segers ◽  
Marcello Rota ◽  
Grazia Esposito ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Combined Treatment ◽  
Volume Ratio ◽  
Experimental Period ◽  
Border Zone ◽  
Myocardial Regeneration ◽  
Prolonged Release ◽  
Cardiac Progenitor Cells ◽  
Receptor System ◽  
Chamber Volume

Cardiac progenitor cells (CPCs) possess the IGF-1-IGF-1 receptor system which promotes cell survival, growth and differentiation. Therefore, we tested whether the local injection of CPCs together with the prolonged release of IGF-1 by self-assembling peptides enhanced myocardial regeneration after infarction. The possibility was raised that this strategy may improve cardiac repair by potentiating the regenerative response of the delivered and resident CPCs. Myocardial infarction was induced in rats and after the injection of 100,000 clonogenic immunocompatible EGFP-positive-CPCs in the border zone, biotinylated IGF-1 nanofibers were delivered to the same region. Four groups of animals were used for comparison: infarcted hearts injected with peptide only, infarcted hearts injected with CPCs only, untreated infarcted hearts and sham operated hearts. All animals received BrdU throughout the 1 month experimental period for the recognition of newly formed cells. Infarct size, ~60%, was comparable in the 4 groups. Although all treated-infarcted hearts showed a reduction in chamber volume and an increase in wall-thickness-to-chamber volume ratio and LV mass-to-chamber volume ratio, the combined treatment had the most positive effect. Similarly, LVEDP, LVDP, and dP/dt improved predominantly in infarcted hearts exposed to CPCs and IGF-1 which possessed a larger number of regenerated myocytes. The newly formed BrdU-positive myocytes consisted of EGFP-positive and EGFP-negative cells. The former category corresponded to the progeny of the injected CPCs and the latter was the product of differentiation of resident CPCs. The regenerated myocytes showed a high degree of differentiation; 20% of myocytes had a volume 2,000 –10,000 μm 3 . This level of maturation was not observed in infarcted hearts treated only with CPCs or IGF1 releasing peptides. Also, administration of CPCs and IGF-1 led to the formation of numerous resistance arterioles and capillary structures within the regenerated myocardium. Thus, the combination of CPCs and IGF-1 biotinylated nanofibers results in an unprecedented degree of myocardial recovery of structure and function after infarction. Importantly, the regenerated myocytes acquire the differentiated adult phenotype.

Variable thickness scroll compressor performance analysis—Part I: Geometric and thermodynamic modeling

2016 ◽  
Vol 231 (4) ◽  
pp. 633-640 ◽  
Author(s):  
Peng Bin ◽  
Vincent Lemort ◽  
Arnaud Legros ◽  
Zhang Hongsheng ◽  
Gong Haifeng
Keyword(s):  
Thermodynamic Modeling ◽  
Variable Thickness ◽  
Geometric Modeling ◽  
Working Fluid ◽  
Base Line ◽  
Scroll Compressor ◽  
Working Chamber ◽  
Chamber Volume ◽  
Gas Heating ◽  
Compressor Performance

In order to investigate the performance of variable thickness scroll compressors, a detail mathematical modeling based on energy and mass balances is established in this two-part. In part I, the geometric modeling and thermodynamic modeling are developed. The profile based on circle involute, high order curve, and arc is built up using the base line method. The volume of working chambers from suction to discharge is defined. Thereafter, the evolution and derivative of the working chamber volume with respect to the orbiting angle are discussed. The energy and the mass balance for working chamber are described. Suction gas heating, radial and flank leakage, heat transfer between the working fluid, scroll wraps and plates are considered in the thermodynamic modeling. The established geometric modeling and thermodynamic modeling can provide better understanding of the variable thickness scroll compressor working process. The dynamical modeling and model validation are reported in part II.

Study on Release Process of Micro-CAES Used Screw Expander

2013 ◽  
Vol 457-458 ◽  
pp. 379-383
Author(s):  
Guang Bin Liu ◽  
Qi Chao Yang ◽  
Ze Gang Qian ◽  
Yuan Yang Zhao ◽  
Le Wang ◽  
...  
Keyword(s):  
System Performance ◽  
Volume Ratio ◽  
Compressed Air ◽  
Suction Pressure ◽  
Total Work ◽  
Average Output ◽  
Release Process ◽  
Chamber Volume ◽  
Constant Suction ◽  
Promising Application

The compressed air energy storage (CAES) has a promising application prospect to ease electic load and match intermittent renewable energy, such as solar and wind energy. The release process influences the output power and system performance. In this paper, a mathematical model is built to simulate the release process of a micro-CAES system with screw expanders. The results show that the rotation angles of suction, expansion and discharge processes are depended on the volume ratio. The chamber volume of 2ndstage expander is larger than the 1ststage one for two expanders. In the constant suction pressure (CSP) condition, the mass remained in the tank is lower slightly than it in the various suction pressure (VSP) condition for the same set pressure in the tank. The CSP condition needs more time to finish the release process. The decrease of air temperature in the CSP condition is smaller than it in the VSP one. The power output decreases with time in the VSP condition, but it is a constant value throughout the release process in the CSP condition. All the average output and the total work in the VSP condition are larger than them in the CSP condition.

A New Cylinder Profile of Double-Action Sliding Vane Compressor and its Three Dimensional Model Based on SolidWorks

2011 ◽  
Vol 105-107 ◽  
pp. 2263-2266
Author(s):  
Chun Hui Lu
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Working Chamber ◽  
Model Based ◽  
Chamber Volume ◽  
Profile Equation ◽  
Compressor Design

Profile is the most important base in double-action compressor design. Different cylinder profile decides different working chamber volume in double-action sliding vane compressor. Five equations of cylinder profile were researched by calculating the working chamber volumes and a new cylinder profile equation of double-action sliding vane compressor was composed to get larger chamber. In same condition with the other equations, the working chamber volume of new profile is bigger than the old profiles over 20 percent while it has no change in the moving and friction characters. And a three dimensional model based on SolidWorks of a new profile was done. Finally, it was assembled successfully in computer to check the design.

scholarly journals Technical Note: Semi-rigid chambers for methane gas flux measurements on tree stems

2016 ◽  
Vol 13 (4) ◽  
pp. 1197-1207 ◽  
Author(s):  
Andy Siegenthaler ◽  
Bertie Welch ◽  
Sunitha R. Pangala ◽  
Michael Peacock ◽  
Vincent Gauci
Keyword(s):  
Continuous Flow ◽  
Gas Permeability ◽  
Volume Ratio ◽  
Technical Note ◽  
Dynamic Mode ◽  
Chamber Volume ◽  
Wide Range ◽  
Flux Measurements ◽  
Ecosystem Flux ◽  
Closed Chambers

Abstract. There is increasing interest in the measurement of methane (CH4) emissions from tree stems in a wide range of ecosystems so as to determine how they contribute to the total ecosystem flux. To date, tree CH4 fluxes are commonly measured using rigid closed chambers (static or dynamic), which often pose challenges as these are bulky and limit measurement of CH4 fluxes to only a very narrow range of tree stem sizes and shapes. To overcome these challenges we aimed to design and test new semi-rigid stem-flux chambers (or sleeves). We compared the CH4 permeability of the new semi-rigid chambers with that of the traditional rigid chamber approach, in the laboratory and in the field, with continuous flow or syringe injections. We found that the semi-rigid chambers had reduced gas permeability and optimal stem gas exchange surface to total chamber volume ratio (Sc / Vtot) better headspace mixing, especially when connected in a dynamic mode to a continuous flow gas analyser. Semi-rigid sleeves can easily be constructed and transported in multiple sizes, are extremely light, cheap to build and fast to deploy. This makes them ideal for use in remote ecosystems where access logistics is complicated.

scholarly journals Technical Note: Semi-rigid chambers for methane gas flux measurements on tree-stems

2015 ◽  
Vol 12 (18) ◽  
pp. 16019-16048
Author(s):  
A. Siegenthaler ◽  
B. Welch ◽  
S. R. Pangala ◽  
M. Peacock ◽  
V. Gauci
Keyword(s):  
Continuous Flow ◽  
Gas Permeability ◽  
Volume Ratio ◽  
Technical Note ◽  
Dynamic Mode ◽  
Chamber Volume ◽  
Wide Range ◽  
Flux Measurements ◽  
Ecosystem Flux ◽  
Closed Chambers

Abstract. There is increasing interest in the measurement of methane (CH4) emissions from tree stems in a wide range of ecosystems so as to determine how they contribute to the total ecosystem flux. To date, tree CH4 fluxes are commonly measured using rigid closed chambers (static or dynamic), which often pose challenges as these are bulky and limit measurement of CH4 fluxes to only a very narrow range of tree stem sizes and shapes. To overcome these challenges we aimed to design, describe and test new semi-rigid stem-flux chambers (or sleeves). We compared semi-rigid chamber's gas permeability to CH4 against the traditional rigid chamber approach, in the laboratory and in the field, with continuous flow or syringe injections. We found that the semi-rigid chambers performed well, and had numerous benefits including reduced gas permeability and optimal stem gas exchange surface to total chamber volume ratio (Sc/Vtot) allowing better headspace mixing, especially when connected in a dynamic mode to a continuous flow gas analyser. Semi-rigid sleeves can easily be constructed and transported in multiple sizes, are extremely light, cheap to build and fast to deploy. This makes them ideal for use in remote ecosystems where access logistics are complicated.

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