On the Dynamics of a Rotary Compressor: Part 2 — Experimental Validation and Sensitivity Analysis

1993 ◽  
Author(s):  
Sisir K. Padhy
Keyword(s):  
Experimental Validation ◽  
Sensitivity Study ◽  
Rotary Compressor ◽  
Dynamics Model ◽  
The Coefficient Of Friction ◽  
The Moment ◽  
Discharge Pressure ◽  
Roller Radius ◽  
Theoretical Results ◽  
Good Agreement

Abstract This paper describes the experimental validation of the rotary compressor dynamics model [1]. Roller velocity is measured using video technology and a very good agreement is found with the theoretical results. A sensitivity study using different variables that affect the compressor dynamics is also carried out. It is found that the coefficient of friction at the vane and roller plays an important role in roller velocity. The dynamics of roller is influenced by the clearances, the roller radius, the vane radius, eccentricity of the shaft, the frictional behavior between the roller ends and the bearing plates, the discharge pressure of the compressor as well as the moment of inertia of roller.

Lubrication Analysis of a Rolling Piston Rotary Compressor: Part 2: Experimental Validation and Results

1994 ◽  
Vol 208 (2) ◽  
pp. 95-104
Author(s):  
S K Padhy
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Validation ◽  
Sensitivity Study ◽  
Rotary Compressor ◽  
Oil Flow ◽  
Different Dimensions ◽  
Rolling Piston ◽  
The Mathematical Model ◽  
Good Agreement

In this paper the experiments conducted for the measurement of oil flow in the rotary compressor are described. The experimental data are compared against the theoretical prediction from the mathematical model developed (1) and a good agreement is found. In addition, experimental data from previously published literature are also used to verify the mathematical model. A sensitivity study is carried out to predict the behaviour of the rotary compressor for the oil flow at different conditions and with different dimensions.

On the Dynamics of a Rotary Compressor: Part 1 — Mathematical Modeling

1993 ◽  
Author(s):  
Sisir K. Padhy
Keyword(s):  
Experimental Validation ◽  
Sensitivity Study ◽  
Solution Procedure ◽  
Rotary Compressor ◽  
Kutta Method ◽  
Air Conditioners ◽  
Runge Kutta Method ◽  
Bearing Dynamics ◽  
The Mathematical Model ◽  
Theoretical Results

Abstract The rotary compressor has been used in room air conditioners as well as in refrigerators for many years. Although a number of published papers has been reported on rotary compressor, in the area of dynamics only a few are found. In addition only one paper describes experimental validation with some agreement with theoretical results. Again the effect of various operating pressures and temperatures, rotational speed of shaft etc. is not fully covered in any published literature. The present paper analyzes the rotary compressor dynamics in detail. The mathematical model, the solution procedure using Runge-Kutta method, and the bearing dynamics are described. The second part of this papers describes the experimental validation and sensitivity study using different variables that affect the compressor dynamics.

Thermal modelling and optimization of heat transfer in a high-temperature theatre luminaire

2003 ◽  
Vol 217 (9) ◽  
pp. 1039-1048 ◽  
Author(s):  
D E Anderson ◽  
T E Truslove ◽  
J Kubie
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Dynamics Model ◽  
Critical Temperatures ◽  
Computational Fluid Dynamics Model ◽  
Extended Surfaces ◽  
Theoretical Results ◽  
Modelling And Optimization ◽  
Good Agreement ◽  
Appreciable Reduction

A computational fluid dynamics model has been developed to predict the thermal performance of high-temperature theatre luminaires. The theoretical results are in good agreement with available experimental data. The model has been used to investigate the behaviour of the thermally sensitive areas of the luminaires. The model shows that an appreciable reduction of critical temperatures can be achieved by using extended surfaces at key locations. The model can also be used to evaluate and optimize future designs.

Band head spin assignment of Tl isotopes of superdeformed rotational bands

Open Physics ◽  
2014 ◽  
Vol 12 (9) ◽  
Author(s):  
Alpana Goel ◽  
Uma Nair ◽  
Archana Yadav
Keyword(s):  
Spin Assignment ◽  
Band Head ◽  
Moment Of Inertia ◽  
Stiffness Parameter ◽  
Transition Energies ◽  
Rotational Bands ◽  
The Moment ◽  
Variable Moment ◽  
Theoretical Results ◽  
Good Agreement

AbstractThe Variable Moment of Inertia (VMI) model is proposed for the assignment of band head spin of super deformed (SD) rotational bands, which in turn is helpful in the spin prediction of SD bands. The moment of inertia and stiffness parameter (C), were calculated by fitting the proposed transition energies. The calculated transition energies are highly dependent on the prescribed spins. The calculated and observed transition energies agree well when an accurate band head spin (I 0) is assigned. The results are in good agreement with other theoretical results reported in literature. In this paper, we have reported the band head spin value 16 rotational band of super deformed Tl isotopes.

Movement characteristics analysis of bi-directional friction linear micro-motor driven by a set of micro-actuator

2021 ◽  
pp. 2140013
Author(s):  
Zhenlu Wang ◽  
Jiue Zhang ◽  
Shuxia Ma ◽  
Guangqiao Liu
Keyword(s):  
Driving Frequency ◽  
Dynamics Model ◽  
Motion Direction ◽  
Movement Characteristics ◽  
Theoretical Predictions ◽  
Characteristics Analysis ◽  
Directional Motion ◽  
The Impact ◽  
Theoretical Results ◽  
Good Agreement

In this paper, a bi-directional friction linear micro-motor (BFLM) driven by a set of micro-actuators was introduced and analyzed. The BFLM was fabricated using PolyMUMPs process. The impact dynamics model for the BFLM was established, and its motion equation was also derived that takes into account the friction and contact. The relative motion between the driving head and the slider, as well as forward or backward movement of the slider were analyzed in detail. The forward and backward movement displacement of the slider was measured, and the experimental results were in good agreement with theoretical predictions. The theoretical results show that the motion direction of the slider can be changed by controllable driving frequency to the BFLM. It was feasible to use a set of actuators to drive the slider in bi-directional motion.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

Studies of local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) crystals

2021 ◽  
Vol 76 (4) ◽  
pp. 299-304
Author(s):  
Fu Chen ◽  
Jian-Rong Yang ◽  
Zi-Fa Zhou
Keyword(s):  
Crystal Field ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic ◽  
Theoretical Results ◽  
Good Agreement

Abstract The electron paramagnetic resonance (EPR) parameters (g factor g i , and hyperfine structure constants A i , with i = x, y, z) and local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) are theoretically investigated using the high order perturbation formulas of these EPR parameters for a 3d 9 ion under orthorhombically elongated octahedra. In the calculations, contribution to these EPR parameters due to the admixture of d-orbitals in the ground state wave function of the Cu2+ ion are taken into account based on the cluster approach, and the required crystal-field parameters are estimated from the superposition model which enables correlation of the crystal-field parameters and hence the studied EPR parameters with the local structures of the Cu2+ centers. Based on the calculations, the Cu–H2O bonds are found to suffer the axial elongation ratio δ of about 3 and 2.9% along the z-axis, meanwhile, the planar bond lengths may experience variation ratio τ (≈3.8 and 1%) along x- and y-axis for Cu2+ center in (NH4)2Zn(SO4)2·6H2O and Rb2Zn(SO4)2·6H2O, respectively. The theoretical results show good agreement with the observed values.

On the Flow Fields of Inertial Impactors

1974 ◽  
Vol 96 (4) ◽  
pp. 394-400 ◽  
Author(s):  
V. A. Marple ◽  
B. Y. H. Liu ◽  
K. T. Whitby
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Relaxation Method ◽  
Water Model ◽  
Navier Stokes ◽  
Visualization Technique ◽  
Navier Stokes Equations ◽  
Theoretical Results ◽  
Plate Distance ◽  
Good Agreement

The flow field in an inertial impactor was studied experimentally with a water model by means of a flow visualization technique. The influence of such parameters as Reynolds number and jet-to-plate distance on the flow field was determined. The Navier-Stokes equations describing the laminar flow field in the impactor were solved numerically by means of a finite difference relaxation method. The theoretical results were found to be in good agreement with the empirical observations made with the water model.

Explanation of the Influence of Inflow Air Content on the Lift of Cavitating Hydrofoils

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Lift Coefficient ◽  
Cavity Surface ◽  
Air Bubbles ◽  
Incoming Flow ◽  
Fluid Density ◽  
Air Content ◽  
Theoretical Results ◽  
Good Agreement

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.

Models for New Corrugated and Porous Solar Air Collectors under Transient Operation

2017 ◽  
Vol 42 (1) ◽  
Author(s):  
Qahtan Adnan Abed ◽  
Viorel Badescu ◽  
Adrian Ciocanea ◽  
Iuliana Soriga ◽  
Dorin Bureţea
Keyword(s):  
Climatic Conditions ◽  
Meteorological Conditions ◽  
Bias Error ◽  
First Order ◽  
Solar Air Collector ◽  
Section Surface ◽  
South Eastern Europe ◽  
Main Components ◽  
Theoretical Results ◽  
Good Agreement

AbstractMathematical models have been developed to evaluate the dynamic behavior of two solar air collectors: the first one is equipped with a V-porous absorber and the second one with a U-corrugated absorber. The collectors have the same geometry, cross-section surface area and are built from the same materials, the only difference between them being the absorbers. V-corrugated absorbers have been treated in literature but the V-porous absorbers modeled here have not been very often considered. The models are based on first-order differential equations which describe the heat exchange between the main components of the two types of solar air heaters. Both collectors were exposed to the sun in the same meteorological conditions, at identical tilt angle and they operated at the same air mass flow rate. The tests were carried out in the climatic conditions of Bucharest (Romania, South Eastern Europe). There is good agreement between the theoretical results and experiments. The average bias error was about 7.75 % and 10.55 % for the solar air collector with “V”-porous absorber and with “U”-corrugated absorber, respectively. The collector based on V-porous absorber has higher efficiency than the collector with U-corrugated absorber around the noon of clear days. Around sunrise and sunset, the collector with U-corrugated absorber is more effective.

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