Comparison Of Electro-Optical Sensor Performance Measurements And Model Predictions In Nonideal Weather: Preliminary Results

1980 ◽  
Author(s):  
William C. Smith ◽  
Roy A. McCrory
Keyword(s):  
Optical Sensor ◽  
Performance Measurements ◽  
Preliminary Results ◽  
Sensor Performance ◽  
Model Predictions

Standard target sets for field sensor performance measurements

2006 ◽  
Author(s):  
John D. O'Connor ◽  
Patrick O'Shea ◽  
John E. Palmer ◽  
Dawne M. Deaver
Keyword(s):  
Performance Measurements ◽  
Sensor Performance ◽  
Field Sensor ◽  
Target Sets

scholarly journals Effect of combination of dye carotene and phycocyanin using daucus carota and spirulina sp. on optical sensor performance

2020 ◽  
Vol 17 (2) ◽  
pp. 907
Author(s):  
Rahmadwati Rahmadwati ◽  
Luthfiyah Rachmawati ◽  
Panca Mudjirahardjo ◽  
Eka Maulana
Keyword(s):  
Optical Sensors ◽  
Optical Sensor ◽  
Daucus Carota ◽  
Spin Coating ◽  
Deposition Method ◽  
Mercury Lamp ◽  
Current Output ◽  
Sensor Performance ◽  
Absorption Of Light ◽  
Light Absorbance

<span>This research designed optical sensors using mercury lamp of 160W. These sensors provided voltage and current output. The design of optical sensors used the organic based material,i.e. dye  carotene and phycocyanin. Fabrication of optical sensor in this research used spin coating deposition method. Based on the results of absorbance test, dye carotene had the largest absorption of light of 2.882 (a.u).  Dye phycocyanin at length had the largest absorption of light of 2.787 (a.u). Combination between dye carotene and phycocyanin, for a 3: 1 (Carotene: Phycocyanin) ratio had a waveform like a dye carotene with a peak of 2.587 (au), whereas for 1: 3 had a waveform like phycocyanin with a peak of 2,279 (au). But, sample 1: 1 ratio had decrement the light absorbance rate with peaks of 1.183 (au). At the voltage testing result, combination of phycocyanin: carotene (1:3) had the best linearity. The response time of dye 3:1 (phycocyanin: carotene), 1:1, 1:3, phycocyanin, and carotene were 6.72 s, 2.469s, 1.171s, 2.66s and 7.01s respectively. </span>

Rotordynamic Performance Measurements and Predictions of a Rotor Supported on Multilayer Gas Foil Journal Bearings for Microturbomachinery

2016 ◽  
Author(s):  
Jongsung Lee ◽  
Young Min Kim ◽  
Moon Sung Park ◽  
Tae Ho Kim ◽  
Kyoung Ku Ha ◽  
...  
Keyword(s):  
Damping Ratio ◽  
Operation Time ◽  
Journal Bearings ◽  
Displacement Sensor ◽  
Radial Clearance ◽  
Performance Measurements ◽  
Displacement Sensors ◽  
Model Predictions ◽  
Type C ◽  
Time Required

This paper presents rotordynamic performance measurements of multilayer gas foil journal bearings (GFJBs) supporting the rotor of oil-free microturbomachinery, and a comparison with the model predictions. A series of rotor coast-down tests from 60 krpm were conducted to compare the rotordynamic performances of three previously developed multilayer GFJBs: types A, B, and C. During the tests, two sets of orthogonally positioned displacement sensors recorded the horizontal and vertical rotor motions, and an axially positioned displacement sensor measured the thrust of the runner axial motion. The test results revealed that the type C GFJBs have a superior rotordynamic capability over the other types. The additional coast-down tests from 100 krpm for the type C showed that the synchronous motions of the rotor are dominant at up to ∼50 krpm, but that large amplitudes of subsynchronous motion associated with the natural frequency of a rotor-GFJB system occur above this speed. Thermal transient response measurements were conducted using four k-type thermocouples at increasing rotor speeds of 20 to 100 krpm with increments of 10 krpm. The operation time required to establish steady-state temperatures was approximately 25 min for each speed. For most of the speeds tested, the front GFJB near the rotor impeller end showed the lowest temperatures, and both the rear GFJB near the thrust runner end and the permanent magnet (PM) motor showed the highest temperatures. The GFTB showed the lowest temperature at low speeds of below 50 krpm, and the highest temperature at the top speed of 100 krpm owing to the increasing axial load caused by the impeller force. The measured impeller pressure and motor output power increased nonlinearly with the increasing rotor speed and fits best with the second-order and third-order polynomial equations, respectively. The measured axial displacement revealed that the rotor moved axially up to ∼ 270 μm toward the impeller side as the speed increased to 100 krpm. Further experiments using a decrease in radial clearance of 30 μm demonstrated a suppression of the large amplitude of the subsynchronous rotor motion to a certain degree. In addition, the onset speed of the subsynchronous motions increased to 80 krpm for the type C GFJBs with the decrease in the radial clearance. Rotordynamic model predictions with the predicted GFJB stiffness and damping coefficients were benchmarked against the test data. The predicted natural frequencies, onset speed of instability (OSI) where the damping ratio became negative, and synchronous rotor response versus speed agreed reasonably with the measured whirl frequencies of the subsynchronous motions, the onset speed of subsynchronous motions (OSS), and the filtered synchronous rotor motion versus speed, respectively. The predictions also showed that the OSI increased from 50 krpm to 80 krpm with a decrease in the radial clearance, thus validating the present rotordynamic model.

Turbulent Hypersonic Flow Effects on Optical Sensor Performance

2018 ◽  
Author(s):  
Lauren E. Mackey ◽  
Iain D. Boyd ◽  
Timothy Leger ◽  
Joseph S. Jewell
Keyword(s):  
Hypersonic Flow ◽  
Optical Sensor ◽  
Sensor Performance ◽  
Flow Effects

scholarly journals Polysaccharides as the Sensing Material for Metal Ion Detection-Based Optical Sensor Applications

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3924 ◽  
Author(s):  
Nur Hidayah Azeman ◽  
Norhana Arsad ◽  
Ahmad Ashrif A Bakar
Keyword(s):  
Optical Sensor ◽  
Metal Ion ◽  
Optical Sensing ◽  
Sensor Applications ◽  
Sensor Performance ◽  
Ion Sensing ◽  
Sensing Material ◽  
Metal Ion Sensing ◽  
Metal Ion Detection ◽  
Physical And Chemical

The incorporation of a proper sensing material towards the construction of high selectivity optical sensing devices is vital. Polysaccharides, such as chitosan and carrageenan, are among the bio-based sensing materials that are extensively employed due to their remarkable physicochemical attributes. This paper highlights the critical aspects of the design of suitable polysaccharides for the recognition of specific analytes through physical and chemical modifications of polysaccharide structure. Such modifications lead to the enhancement of physicochemical properties of polysaccharides and optical sensor performance. Chitosan and carrageenan are two materials that possess excellent features which are capable of sensing target analytes via various interactions. The interaction between polysaccharides and analytes is dependent on the availability of functional groups in their structure. The integration of polysaccharides with various optical sensing techniques further improves optical sensor performance. The application of polysaccharides as sensing materials in various optical sensing techniques is also highlighted, particularly for metal ion sensing.

scholarly journals Fiber Bragg Grating Sensors Integrated in Polymeric Foils

2010 ◽  
Vol 636-637 ◽  
pp. 1548-1554 ◽  
Author(s):  
A.F. Silva ◽  
F. Gonçalves ◽  
L.A.A. Ferreira ◽  
F.M. Araújo ◽  
P.M. Mendes ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Optical Sensors ◽  
Optical Sensor ◽  
Industrial Process ◽  
High Sensitivity ◽  
Bragg Grating ◽  
Element Analysis ◽  
Fiber Sensors ◽  
Sensor Performance ◽  
Fiber Bragg Grating Sensors

Optical sensors have hit their maturity and a new kind of systems is being developed. This paper deals with the development of a new sensing structure based on polymeric foils and optic fiber sensors, namely the Fiber Bragg Grating sensors. Sensor integration in polymeric foils, using industrial process is the proposed goal. To achieve this goal, Finite Element Analysis was used for prototype modeling and simulation. The model was subjected to loads and restraints in order to retrieve information about stress distribution and displacement of specific points. From the simulation was possible to predict the sections where the sensor should be positioned. A prototype was then fabricated using industrial processes. Tests indicate that the polymeric foil influence on the sensor performance may exist. However, the prototype was able of transferring the full deformation to the optical sensor. Moreover, the optical sensor, which is incorporated in the polymeric foil, is fully functional with high sensitivity, 0.6 picometer by microstrain, allowing deformation measurements, up to 1.2 millimeter.

Rotordynamic Performance of Shimmed Gas Foil Bearings for Oil-Free Turbochargers

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Kyuho Sim ◽  
Lee Yong-Bok ◽  
Tae Ho Kim ◽  
Jangwon Lee
Keyword(s):  
Diesel Engine ◽  
Test Data ◽  
Compressed Air ◽  
Radial Clearance ◽  
Bench Test ◽  
Test Results ◽  
Passenger Vehicle ◽  
Performance Measurements ◽  
Foil Bearings ◽  
Model Predictions

Oil-free turbochargers (TCs) will increase the power and efficiency of internal combustion engines, both sparking ignition and compression ignition, without engine oil lubricant feeding or scheduled maintenance. Using gas foil bearings (GFBs) in passenger vehicle TCs enables compact, lightweight, oil-free systems, along with accurate shaft motion. This paper presents extensive test measurements on GFBs for oil-free TCs, including static load-deflection measurements of test GFBs, rotordynamic performance measurements of a compressed air driven oil-free TC unit supported on test GFBs, and bench test measurements of the oil-free TC driven by a passenger vehicle diesel engine. Two configurations of GFBs, one original and the other modified with three shims, are subjected to a series of experimental tests. For the shimmed GFB, three metal shims are inserted under the bump-strip layers, in contact with the bearing housing. The installation of shims creates mechanical preloads that enhance a hydrodynamic wedge in the assembly radial clearance to generate more film pressure. Simple static load-deflection tests estimate the assembly radial clearance of the shimmed GFB, which is smaller than that of the original GFB. Model predictions agree well with test data. The discrepancy between the model predictions and test data is attributed to fabrication inaccuracy in the top foil and bump strip layers. Test GFBs are installed into a TC test rig driven by compressed air for rotordynamic performance measurements. The test TC rotor, 335 g in weight and 117 mm long, is coated with a commercially available, wear-resistant solid lubricant, Amorphous M, to prevent severe wear during start-up and shutdown in the absence of an air film. A pair of optical proximity probes positioned orthogonally at the compressor end record lateral rotor motions. Rotordynamic test results show that the shimmed GFB significantly diminishes the large amplitude of subsynchronous rotor motions arising in the unmodified GFB. Predicted synchronous rotor amplitudes and rigid body mode natural frequencies agree reasonably well with recorded test data. Finally, the oil-free TC is installed into a passenger vehicle diesel engine test bench. The TC rotor speed is controlled by the vehicle engine. Speed-up tests show dominant synchronous motion (1X) of the rotor. Whirl frequencies of the relatively small subsynchronous motions are associated with the rigid body natural mode of the TC rotor-GFB system as well as (forced) excitation from the four-cylinder diesel engine. The bench test measurements demonstrate a significant reduction in the amplitude of subsynchronous motions for the shimmed GFB, thus verifying the preliminary test results in the TC test rig driven by compressed air.

Development and Performance Measurements of a Beta-Type Free-Piston Stirling Engine Along With Dynamic Model Predictions

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Kyuho Sim ◽  
Dong-Jun Kim
Keyword(s):  
Dynamic Model ◽  
Stirling Engine ◽  
Electric Heater ◽  
Performance Measurements ◽  
Free Piston ◽  
Dynamic Behaviors ◽  
Output Performance ◽  
Model Predictions ◽  
And Performance ◽  
Free Piston Stirling Engine

This paper presents the development and performance measurements of a beta-type free-piston Stirling engine (FPSE) along with dynamic model predictions. The FPSE is modeled as a two degrees-of-freedom (2DOF) vibration system with the equations of motion for displacer and piston masses, which are connected to the spring and damping elements and coupled by working pressure. A test FPSE is designed from root locus analyses and developed with flexure springs and a dashpot load. The stiffness of the test springs and the damping characteristics of the dashpot are identified through experiments. An experimental test rig is developed with an electric heater and a water cooler, operating under the atmospheric air. The piston dynamic behaviors, including the operating frequency, piston stroke, and phase angle, and engine output performance are measured at various heater temperatures and external loads. The experimental results are compared to dynamic model predictions. The test FPSE is also compared to a conventional kinematic engine in terms of engine output performance and dynamic adaptation to environments. Incidentally, nonlinear dynamic behaviors are observed during the experiments and discussed in detail.

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