scholarly journals Investigation on the Suction Reed Valve Motion with Sticky Force in a Refrigerator Compressor

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2897 ◽  
Author(s):  
Wei Zhang ◽  
Lantian Ji ◽  
Ziwen Xing ◽  
Xueyuan Peng
Keyword(s):  
Experimental Investigation ◽  
Significant Influence ◽  
Strain Gauge ◽  
Power Loss ◽  
Pressure Pulsation ◽  
Pressure Sensors ◽  
Differential Pressure ◽  
Experimental Conditions ◽  
Valve Motion ◽  
Reed Valve

The valve motion strongly couples with the differential pressure between the cylinder and the suction and discharge plenum, which has a significant influence on the performance of the refrigerator compressor. To examine the interaction between the pressure and the reed valve motion, this paper presents an experimental investigation into the inner workings of the refrigerator compressor, particularly the p-V diagram and the motion of the suction valve. The refrigerator compressor was modified to conveniently mount the sensors. Three pressure sensors were installed to measure the p-V diagram and pressure pulsation, while a strain gauge was employed to measure the motion of the suction valve. The interaction between the differential pressure and the valve motion were clearly observed from the experimental results. It was found that there was a considerable power loss up to 14.5% in the suction process under experimental conditions. The sticky force of the oil had a significant effect on both the motion of the suction valve and the suction phase of the compressor. The delayed opening of the reed valve increased the amplitude of the pressure pulsation in the suction plenum. The experimental method which integrates the pressure variety and the valve movement proposed in this paper could contribute to the efficient testing and the optimization of the refrigerator compressor.

Intraoral Air Pressure and Oral Air Flow Under Different Bleed and Bite-Block Conditions

1986 ◽  
Vol 29 (1) ◽  
pp. 37-49 ◽  
Author(s):  
Anne H.B. Putnam ◽  
Ralph L. Shelton ◽  
Charles U. Kastner
Keyword(s):  
Differential Pressure ◽  
Respiratory Drive ◽  
Air Leakage ◽  
Experimental Conditions ◽  
Bite Block ◽  
Orifice Area ◽  
Release Device ◽  
Intraoral Air Pressure ◽  
Intraoral Pressure ◽  
Production Characteristics

Intraoral pressures and oral flows were measured as normal talkers produced /p/ and /si/ under experimental conditions that perturbed the usual aeromechanical production characteristics of the consonants. A translabial pressure-release device was used to bleed off intraoral pressure during /p/. Bite—blocks were used to open the anterior bite artificially during /s/. For /p/, intraoral pressure decreased and translabial air leakage increased as bleed orifice area increased. For /s/, flow increased as the area of sibilant constriction increased, but differential pressure across the /s/ oral constriction did not vary systematically with changes in its area. Flow on postconsonantal vowels // and /i/ did not vary systematically across experimental conditions. The data imply that maintenance of perturbed intraoral pressure was more effective when compensatory options included opportunity for increased respiratory drive and structural adjustments at the place of consonant articulation rather than increased respiratory drive alone.

Characteristics of Miniature Short-Tube Orifice Flows

1989 ◽  
Vol 203 (5) ◽  
pp. 351-358 ◽  
Author(s):  
T A Fox ◽  
J Stark
Keyword(s):  
Experimental Investigation ◽  
Critical Pressure ◽  
Fuel Injection ◽  
Flow Characteristics ◽  
Head Loss ◽  
Differential Pressure ◽  
Pressure Differential ◽  
Contraction Parameter ◽  
Volumetric Discharge ◽  
Short Tube

This paper presents the results of an experimental investigation into the flow characteristics of miniature short-tube orifices of a type commonly used for fuel injection. From measurements of differential pressure and volumetric discharge it is shown that these devices are susceptible to a cavitation-induced instability phenomenon known as hydraulic flip. It was found that this instability is limited to orifices of length less than fourteen diameters and occurs at a critical pressure differential which varies as a function of the orifice l/d ratio and contraction parameter β. In addition, the performance of the device is examined in terms of the head loss characteristics and it is shown that the mechanisms associated with hydraulic flip have a significant effect on the efficiency of discharge.

Differential Pressure Sensors for Underwater Speedometry in Variable Velocity and Acceleration Conditions

2018 ◽  
pp. 1-9 ◽  
Author(s):  
Juan Francisco Fuentes-Perez ◽  
Christian Meurer ◽  
Jeffrey Andrew Tuhtan ◽  
Maarja Kruusmaa
Keyword(s):  
Pressure Sensors ◽  
Differential Pressure ◽  
Variable Velocity

Design, development and performance evaluation of pressure sensor using eddy current displacement sensing coil

Sensor Review ◽  
2018 ◽  
Vol 38 (2) ◽  
pp. 248-258
Author(s):  
Gobi K. ◽  
Kannapiran B. ◽  
Devaraj D. ◽  
Valarmathi K.
Keyword(s):  
Performance Evaluation ◽  
Eddy Current ◽  
Pressure Sensor ◽  
Strain Gauge ◽  
Pressure Sensors ◽  
Calibration Data ◽  
Position Measurement ◽  
Content Type ◽  
Short Period ◽  
Type Pressure

Purpose The conventional strain gauge type pressure sensor suffers in static testing of engines due to the contact transduction method. This paper aims to focus on the concept of non-contact transduction-based pressure sensor using eddy current displacement sensing coil (ECDS) to overcome the temperature limitations of the strain gauge type pressure sensor. This paper includes the fabrication of prototypes of the proposed pressure sensor and its performance evaluation by static calibration. The fabricated pressure sensor is proposed to measure pressure in static test environment for a short period in the order of few seconds. The limitations of the fabricated pressure sensor related to temperature problems are highlighted and the suitable design changes are recommended to aid the future design. Design/methodology/approach The design of ECDS-based pressure sensor is aimed to provide non-contact transduction to overcome the limitations of the strain gauge type of pressure sensor. The ECDS is designed and fabricated with two configurations to measure deflection of the diaphragm corresponding to the applied pressure. The fabricated ECDS is calibrated using a standard micro meter to ensure transduction within limits. The fabricated prototypes of pressure sensors are calibrated using dead weight tester, and the calibration results are analyzed to select the best configuration. The proposed pressure sensor is tested at different temperatures, and the test results are analyzed to provide recommendations to overcome the shortcomings. Findings The performance of the different configurations of the pressure sensor using ECDS is evaluated using the calibration data. The analysis of the calibration results indicates that the pressure sensor using ECDS (coil-B) with the diaphragm as target is the best configuration. The accuracy of the fabricated pressure sensor with best configuration is ±2.8 per cent and the full scale (FS) output is 3.8 KHz. The designed non-contact transduction method extends the operating temperature of the pressure sensor up to 150°C with the specified accuracy for the short period. Originality/value Most studies of eddy current sensing coil focus on the displacement and position measurement but not on the pressure measurement. This paper is concerned with the design of the pressure sensor using ECDS to realize the non-contact transduction to overcome the limitations of strain gauge type pressure sensors and evaluation of the fabricated prototypes. It is shown that the accuracy of the proposed pressure sensor is not affected by the high temperature for the short period due to non-contact transduction using ECDS.

Method of metrological self-checking of a strain gauge pressure sensor

Metrologiya ◽  
2020 ◽  
pp. 48-62
Author(s):  
Vladimir A. Larionov
Keyword(s):  
Strain Gauge ◽  
Supply Voltage ◽  
Experimental Studies ◽  
Pressure Sensors ◽  
Experimental Sample ◽  
Self Monitoring ◽  
Gauge Pressure ◽  
External Conditions ◽  
Temperature And Pressure ◽  
Overall Resistance

Existing methods of metrological self-monitoring of measuring sensors for temperature and pressure of technological industries are considered. The analysis of methods of metrological self-checking of strain gauge pressure sensors is carried out. Method is proposed based on measuring the supply voltage and voltage on the measuring diagonal of the bridge. The temperature of the strain gauge bridge is determined using a semiconductor thermistor installed near the bridge. This allows you to adjust the measured value of the total resistance of the bridge from the temperature of the bridge. With aging and exposure to external conditions, a change in the overall resistance of the bridge can be used to judge the error of the sensor. An experimental sample of the sensor was made. The failure of the strain gage bridge is simulated by parallel connection of an additional resistor to one of the shoulders of the bridge. Experimental studies have shown that modern technical means make it possible to assess the effect of changes in the total bridge resistance on the sensor error.

scholarly journals 3D Printed Flowmeter Based on Venturi Effect with Integrated Pressure Sensors

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1509 ◽  
Author(s):  
Krzysztof Adamski ◽  
Bartosz Kawa ◽  
Rafał Walczak
Keyword(s):  
Liquid Flow ◽  
Pressure Sensors ◽  
Differential Pressure ◽  
Single Chip ◽  
Flow Meter ◽  
Modular Systems ◽  
Venturi Effect ◽  
3D Printed

In this paper we present a 3D printed flow meter based on venturri effect. Dimensions of the microchannels are 800 µm for wider and 400 µm for thinker channel. Application of different type of sensors was investigated: differential, absolute and digital barometer. Results of measurement of differential pressure and calculation of liquid flow are shown. Presented microfluidics device can be also easy adapted for modular systems. Presented flow meter is the first integration of commercial available sensors and 3D printed microfluidics structure in a single chip.

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