In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids
The capabilities of Fiber Bragg Grating (FBG) sensors to measure temperature variations in the bulk of liquid flows were considered. In the first step of our research project, reported in this paper, we investigated to what extent the use of thin glass fibers without encapsulation, which only minima...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-10-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/23/20/8539 |
| _version_ | 1827719841558036480 |
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| author | Sylvie Su Tianyi Niu Tobias Vogt Sven Eckert |
| author_facet | Sylvie Su Tianyi Niu Tobias Vogt Sven Eckert |
| author_sort | Sylvie Su |
| collection | DOAJ |
| description | The capabilities of Fiber Bragg Grating (FBG) sensors to measure temperature variations in the bulk of liquid flows were considered. In the first step of our research project, reported in this paper, we investigated to what extent the use of thin glass fibers without encapsulation, which only minimally disturb a flow, can fulfill the requirements for robustness and measurement accuracy. Experimental tests were performed in a benchmark setup containing 24 FBG measuring positions, which were instrumented in parallel with thermocouples for validation. We suggest a special assembly procedure in which the fiber is placed under a defined tension to improve its stiffness and immobility for certain flow conditions. This approach uses a single FBG sensor as a reference that measures the strain effect in real time, allowing accurate relative temperature measurements to be made at the other FBG sensor points, taking into account an appropriate correction term. Absolute temperature readings can be obtained by installing another well-calibrated, strain-independent thermometer on the reference FBG. We demonstrated this method in two test cases: (i) a temperature gradient with stable density stratification in the liquid metal GaInSn and (ii) the heating of a water column using a local heat source. In these measurements, we succeeded in recording both spatial and temporal changes in the linear temperature distribution along the fiber. We present the corresponding results from the tests and, against this background, we discuss the capabilities and limitations of this measurement technique with respect to the detection of temperature fields in liquid flows. |
| first_indexed | 2024-03-10T20:54:25Z |
| format | Article |
| id | doaj.art-1b72db9b961b40c6815de1429848eb36 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T20:54:25Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-1b72db9b961b40c6815de1429848eb362023-11-19T18:04:28ZengMDPI AGSensors1424-82202023-10-012320853910.3390/s23208539In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in FluidsSylvie Su0Tianyi Niu1Tobias Vogt2Sven Eckert3Helmholtz-Zentrum Dresden–Rossendorf, Bautzner Landstraße 400, 01328 Dresden, GermanyHelmholtz-Zentrum Dresden–Rossendorf, Bautzner Landstraße 400, 01328 Dresden, GermanyHelmholtz-Zentrum Dresden–Rossendorf, Bautzner Landstraße 400, 01328 Dresden, GermanyHelmholtz-Zentrum Dresden–Rossendorf, Bautzner Landstraße 400, 01328 Dresden, GermanyThe capabilities of Fiber Bragg Grating (FBG) sensors to measure temperature variations in the bulk of liquid flows were considered. In the first step of our research project, reported in this paper, we investigated to what extent the use of thin glass fibers without encapsulation, which only minimally disturb a flow, can fulfill the requirements for robustness and measurement accuracy. Experimental tests were performed in a benchmark setup containing 24 FBG measuring positions, which were instrumented in parallel with thermocouples for validation. We suggest a special assembly procedure in which the fiber is placed under a defined tension to improve its stiffness and immobility for certain flow conditions. This approach uses a single FBG sensor as a reference that measures the strain effect in real time, allowing accurate relative temperature measurements to be made at the other FBG sensor points, taking into account an appropriate correction term. Absolute temperature readings can be obtained by installing another well-calibrated, strain-independent thermometer on the reference FBG. We demonstrated this method in two test cases: (i) a temperature gradient with stable density stratification in the liquid metal GaInSn and (ii) the heating of a water column using a local heat source. In these measurements, we succeeded in recording both spatial and temporal changes in the linear temperature distribution along the fiber. We present the corresponding results from the tests and, against this background, we discuss the capabilities and limitations of this measurement technique with respect to the detection of temperature fields in liquid flows.https://www.mdpi.com/1424-8220/23/20/8539optical fiberFiber Bragg Grating (FBG)temperature sensorin-bulk measurementmultiplexingtemperature mapping |
| spellingShingle | Sylvie Su Tianyi Niu Tobias Vogt Sven Eckert In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids Sensors optical fiber Fiber Bragg Grating (FBG) temperature sensor in-bulk measurement multiplexing temperature mapping |
| title | In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids |
| title_full | In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids |
| title_fullStr | In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids |
| title_full_unstemmed | In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids |
| title_short | In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids |
| title_sort | in bulk temperature profile mapping using fiber bragg grating in fluids |
| topic | optical fiber Fiber Bragg Grating (FBG) temperature sensor in-bulk measurement multiplexing temperature mapping |
| url | https://www.mdpi.com/1424-8220/23/20/8539 |
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