Experimental investigation of angle dependent torque properties of a particle rotary damper using a magnetic elastomer particle assemblage

2020 ◽  
Vol 64 (1-4) ◽  
pp. 737-743
Author(s):  
Kathir Kishan Kalaiselvan ◽  
Yasushi Ido ◽  
Yuhiro Iwamoto ◽  
Atsushi Toyouchi
Keyword(s):  
Experimental Investigation ◽  
Rotational Speed ◽  
Carbonyl Iron ◽  
Packing Fraction ◽  
Experimental Investigations ◽  
Damping Capacity ◽  
Percentage Increase ◽  
Constant Torque ◽  
Typical Particle ◽  
Ferromagnetic Particles

Typical particle rotary dampers generate constant torque throughout the cycle of rotation. However, this research is focused on generating angle dependent torque i.e. different torque at different angles. The damper is designed to generate an elevated torque at a specific angle. This can be achieved by employing ferromagnetic particles and by introducing a permanent magnet in the damper. This study is carried out using two major parameters I) base torque which is the measure of damping capacity and II) percentage increase in torque which is the measure of angle dependency. From the experimental investigations, it has been found that I) base torque increases with packing fraction and rotational speed and decreases conditionally with the amount of carbonyl iron present in the particle while II) percentage increase in torque decreases with packing fraction, remains constant with rotational speed and increases conditionally with the amount of carbonyl iron present in the particle.

Experimental investigations on finishing of a brass specimen by magneto-rheological honing technique

2021 ◽  
pp. 251659842110157
Author(s):  
Chinu Kumari ◽  
Sanjay Kumar Chak
Keyword(s):  
Magnetic Field ◽  
Process Parameters ◽  
Surface Finish ◽  
Rotational Speed ◽  
Field Application ◽  
Surface Finishing ◽  
Experimental Investigations ◽  
Significant Parameter ◽  
Magnetizing Current ◽  
Magneto Rheological

Magneto-rheological abrasive honing (MRAH) is an unconventional surface finishing technique that relies on abrasives mixed with a unique finishing fluid, which changes its characteristics on magnetic field application. This process imparts nanometric-level surface finish with a significant amount of uniformity. Rotating motion of the workpiece and continuous reciprocation of the finishing fluid in the MRAH process are recognized as the major aspects for adopting this process in finishing non-magnetic materials. The finishing obtained through the MRAH process relies on the workpiece’s material properties and process parameters such as concentration of abrasives in finishing fluid, rotational speed of the workpiece, and magnetic field strength/magnetizing current. To study the efficacy of MRAH process, a parametric study was conducted by performing few experiments on a brass workpiece. Design of experiment approach was adopted to plan the experiments, and the effect of different values of magnetizing current, the concentration of abrasives, and rotational speed on the surface finish were analyzed through the application of analysis of variance (ANOVA). From ANOVA, the rotational speed was found as the most significant parameter with a contribution of 48.90% on % reduction in roughness value (%∇Ra). Around 57% of roughness reduction was obtained at the optimized value of process parameters.

High-Frequency Yarn Tension Variations in Spinning

1980 ◽  
Vol 102 (1) ◽  
pp. 45-50
Author(s):  
E. Dyson ◽  
G. Afshari
Keyword(s):  
Experimental Investigation ◽  
Periodic Structure ◽  
Coefficient Of Variation ◽  
Rotational Speed ◽  
High Frequency ◽  
Ring Spinning ◽  
Statistical Parameters ◽  
Yarn Tension ◽  
Rotor Spinning

A description of an experimental investigation of the variations in yarn tension during both ring and rotor open-end spinning which have frequencies equal to, or greater than, the rotational speed of the system is given. Typical results are illustrated and discussed both in terms of statistical parameters such as the coefficient of variation and in terms of their spectra. Tension variations during rotor spinning are shown to have, in general, a much less pronounced periodic structure then the corresponding variations during ring spinning.

scholarly journals Test Rig for Applied Experimental Investigations of the Thermal Contact Resistance at the Blade-Rotor-Connection in a Steam Turbine

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Dennis Toebben ◽  
Xavier E. R. de Graaf ◽  
Piotr Luczynski ◽  
Manfred Wirsum ◽  
Wolfgang F. D. Mohr ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Steam Turbine ◽  
Contact Pressure ◽  
Rotational Speed ◽  
Thermal Contact Resistance ◽  
Thermal Stresses ◽  
Thermal Contact ◽  
Experimental Investigations ◽  
Molybdenum Steel ◽  
Bottle Neck

Recent studies have shown that in a prewarming, respectively, warm-keeping operation of a steam turbine, the blades and vanes transport most of the heat to the thick-walled casing and rotor. Thereby, a thermal bottle-neck arises at the connection between the blade root and the rotor. The thermal contact resistance (TCR) at these interfaces affects the temperature distribution and thus the thermal stresses in the rotor. The present paper introduces an experimental setup, which is designed to quantify the TCR at the blade-rotor-connection of a steam turbine. An uncertainty analysis is presented, which proves that the average measurement uncertainties are less than one percent. The experiments especially focus on the investigation of the contact pressure, which is a function of the rotational speed. Therefore, the results of several steady-state measurements under atmospheric and evacuated atmosphere using a high temperature-resistant chromium-molybdenum steel are presented. For the evaluation of the TCR, a numerical model of the specimen is developed in addition to a simplified 1D approach. The results show a significantly increasing TCR with decreasing contact pressure, respectively, rotational speed.

scholarly journals The practice of experimental investigations of lexical tones in Baltic subdialects: some of the new insights in methodology

2020 ◽  
pp. 1-19
Author(s):  
Evaldas Švageris
Keyword(s):  
Experimental Investigation ◽  
Methodological Approach ◽  
Main Idea ◽  
Experimental Investigations ◽  
Lexical Tone ◽  
Mathematical Functions ◽  
Combined Analysis ◽  
Lexical Tones ◽  
Acoustic Correlates ◽  
The Baltic

This article provides an alternative way of experimental investigation of lexical tones in the Baltics. The main idea holds on a presupposition that the phonetic basis of prosodic elements in question can be explained in a more appropriate way in terms of a combined analysis of acoustic correlates, rather than a selective one. The lexical tone in this case may be interpreted as a factor which determines the type of acoustic correlation. Ideally, the interdependence of that sort could be defined by mathematical functions. The analysis of the empirical basis provides clear evidence in the favour of such methodological approach. Phonetic data from both, the Latvian (Valmiera) and the Lithuanian (North Žemaitian) subdialects confirmed clearly that the highest level of the tone distinction can be reached by a combined analysis of the pitch slope, pitch jerk and the duration of the long accented vowels. These results have arguably improved the interpretation of the phonetic tone structure and shed a new light on the typological links between the Baltic dialects. Finally, it presupposes that the phonetic nature of prosodic elements in some degree depends on a methodological way we choose for the investigational purposes. 

scholarly journals Experimental investigations of the performance of a thermoacoustic electricity generator

2019 ◽  
Vol 116 ◽  
pp. 00025
Author(s):  
Ahmed Hamood ◽  
Artur Jaworski
Keyword(s):  
Experimental Investigation ◽  
Acoustic Wave ◽  
Load Resistance ◽  
Experimental Investigations ◽  
The Novel ◽  
Working Medium ◽  
Linear Alternator ◽  
Mean Pressure ◽  
Set Up ◽  
Working Parameters

This paper presents the experimental investigation of a two-stage thermoacoustic electricity generator able to convert heat at the temperature of the exhaust gases of an internal combustion into useful electricity. The novel configuration is one wavelength and consists of two identical stages. The identical stages will have out of phase acoustic wave at similar amplitudes which allows coupling a linear alternator to run in push-pull mode. The experimental set-up is 16.1 m long and runs at 54.7 Hz. The working medium is helium at 28 bar. The maximum generated electric power is 73.3 W at 5.64% thermal-to-electric efficiency. The working parameters including load resistance, mean pressure and heating power were investigated.

Experimental Investigation of Problems of Drift in Aerial Spraying

2019 ◽  
pp. 1-12
Author(s):  
Robert S. Rowiński
Keyword(s):  
Experimental Investigation ◽  
Crop Protection ◽  
Main Topic ◽  
Experimental Investigations ◽  
Protection Zones ◽  
Aerial Spraying

Agricultural and forestry requirements for agricultural aviation are related to spread of fertilizers, crop protection and protection against pests in forestry. Main topic presented on this paper is the result of experimental investigations in the field of “the drift in aerial spraying”. The results of those investigations are formulas for estimating protection zones depending on the type of used pesticides.

Experimental Investigations of MREs Behavior under the Cyclic Load

2011 ◽  
Vol 183 ◽  
pp. 163-168 ◽  
Author(s):  
Grzegorz Slawinski ◽  
Danuta Miedzińska ◽  
Tadeusz Niezgoda ◽  
Anna Boczkowska
Keyword(s):  
Magnetic Field ◽  
Testing Machine ◽  
Hysteresis Loops ◽  
Vertical Axis ◽  
Experimental Investigations ◽  
Materials Testing ◽  
Variable Load ◽  
Dynamic Tests ◽  
Static And Dynamic Loads ◽  
Ferromagnetic Particles

In the paper the experimental results of the dynamic tests of the MRE samples cured without and under magnetic field are presented and compared. The samples (55 mm diameter and 70 mm) were made of the polyurethane elastomer PU 70/30 with the admixture of the ferromagnetic particles (in this case – carbonyl iron spheres with the diameter of about 9 μm). The samples with ferromagnetic particles were cured without as well as under the external, parallel to the vertical axis of the sample, magnetic field of the 300 mT intensity. The experiments were carried out on the materials testing machine for static and dynamic loads INSTRON 8802. The machine was additionally equipped with the measurement head of 4kN scope and the magnetic coil that produces the magnetic field of the intensity up to 500 mT. Cycled load was applied to the MRE samples. In the case of the dynamic tests the sinusoid cyclic variable load was used. The applied load frequency was 1 Hz in each presented test. The samples were cyclically compressed of the 10, 15, 20 and 25 % of their height. On the base of the obtained results the force maximum values and the dumping coefficient (the energy dissipation coefficient) in each dynamic tests were calculated. The hysteresis loops in the load – displacement charts that were observed during the cyclic tests. The influence of the internal structure of the researched material on its strength behaviour is taken into consideration.

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