{"id":{"repo_id":"wvu","oai_identifier":"oai:researchrepository.wvu.edu:etd-2018"},"canonical_url":"https://search.dev.ndltd.org/etd/wvu/oai:researchrepository.wvu.edu:etd-2018","repository":{"repo_id":"wvu","name":"West Virginia University","base_url":"https://researchrepository.wvu.edu/do/oai/"},"display":{"title":"Point Doppler velocimetry measurements in circular jets","abstract":"Improvements have been made to an existing 2-component Point Doppler Velocimetry (PDV) system to improve instrument accuracy and repeatability and to reduce mean velocity offset. Most importantly, the original iodine cells have been replaced by vapor-limited iodine cells that are not influenced by room temperature variations. PDV is a non-intrusive laser based flow measurement technique with capabilities that are similar to hot wire anemometry, but without inserting a probe into the flow. The insertion of a probe into a flow can affect the flow, resulting in inaccurate measurements.;PDV measurements for 1 inch diameter standard, swirling, and annular jets have been made at a nominal exit velocity of 60 m/s, corresponding to a Reynolds number of 100,000. Measurements of radial profiles of mean and RMS velocities were taken for each jet from the jet exit to X/D=12 at nine different X locations. Also, centerline velocity profiles were taken from the jet exit to X/D=12. Comparisons between hot wire anemometry and PDV measurements have been made for standard and swirling jets, and PDV data repeatability has been judged by multiple runs for each jet.;Hot wire anemometry measurements in the swirling jet appear to be inaccurate for X/D ≤ 4 due to the inability of the hot wire anemometer to accurately measure two-dimensional flow velocities. The PDV and hot wire comparisons for the standard jet have good correlation for the mean velocity; however, the RMS velocities do not agree. PDV measurements of the axial and circumferential mean velocities exhibited an uncertainty and repeatability of 2 m/s. This error, for the axial mean velocity, was of the same order as was produced by using a different calibration from the same day. PDV RMS velocities exhibited a repeatability of 0.5--1.0 m/s, and generally are about one half as large as the hot wire anemometer RMS velocities.","abstract_html":"Improvements have been made to an existing 2-component Point Doppler Velocimetry (PDV) system to improve instrument accuracy and repeatability and to reduce mean velocity offset. Most importantly, the original iodine cells have been replaced by vapor-limited iodine cells that are not influenced by room temperature variations. PDV is a non-intrusive laser based flow measurement technique with capabilities that are similar to hot wire anemometry, but without inserting a probe into the flow. The insertion of a probe into a flow can affect the flow, resulting in inaccurate measurements.;PDV measurements for 1 inch diameter standard, swirling, and annular jets have been made at a nominal exit velocity of 60 m/s, corresponding to a Reynolds number of 100,000. Measurements of radial profiles of mean and RMS velocities were taken for each jet from the jet exit to X/D=12 at nine different X locations. Also, centerline velocity profiles were taken from the jet exit to X/D=12. Comparisons between hot wire anemometry and PDV measurements have been made for standard and swirling jets, and PDV data repeatability has been judged by multiple runs for each jet.;Hot wire anemometry measurements in the swirling jet appear to be inaccurate for X/D ≤ 4 due to the inability of the hot wire anemometer to accurately measure two-dimensional flow velocities. The PDV and hot wire comparisons for the standard jet have good correlation for the mean velocity; however, the RMS velocities do not agree. PDV measurements of the axial and circumferential mean velocities exhibited an uncertainty and repeatability of 2 m/s. This error, for the axial mean velocity, was of the same order as was produced by using a different calibration from the same day. PDV RMS velocities exhibited a repeatability of 0.5--1.0 m/s, and generally are about one half as large as the hot wire anemometer RMS velocities.","abstract_has_math":false,"creators":["Collins, Patrick Michael"],"institution":null,"degree_name":"MS","degree_level":"Thesis","degree_discipline":"Mechanical and Aerospace Engineering","degree_department":null,"school":null,"contributors":["John M. Kuhlman."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2000,"date_issued":"2000-05-01T07:00:00Z","date_published":"2000-05-01T07:00:00Z","updated_at":"2026-07-24T06:15:08Z","subjects":["Mechanical engineering","Aerospace engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://researchrepository.wvu.edu/etd/1015"],"render_values":[{"text":"https://researchrepository.wvu.edu/etd/1015","href":"https://researchrepository.wvu.edu/etd/1015","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.33915/etd.1015","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["John M. 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Most importantly, the original iodine cells have been replaced by vapor-limited iodine cells that are not influenced by room temperature variations. PDV is a non-intrusive laser based flow measurement technique with capabilities that are similar to hot wire anemometry, but without inserting a probe into the flow. The insertion of a probe into a flow can affect the flow, resulting in inaccurate measurements.;PDV measurements for 1 inch diameter standard, swirling, and annular jets have been made at a nominal exit velocity of 60 m/s, corresponding to a Reynolds number of 100,000. Measurements of radial profiles of mean and RMS velocities were taken for each jet from the jet exit to X/D=12 at nine different X locations. Also, centerline velocity profiles were taken from the jet exit to X/D=12. Comparisons between hot wire anemometry and PDV measurements have been made for standard and swirling jets, and PDV data repeatability has been judged by multiple runs for each jet.;Hot wire anemometry measurements in the swirling jet appear to be inaccurate for X/D ≤ 4 due to the inability of the hot wire anemometer to accurately measure two-dimensional flow velocities. The PDV and hot wire comparisons for the standard jet have good correlation for the mean velocity; however, the RMS velocities do not agree. PDV measurements of the axial and circumferential mean velocities exhibited an uncertainty and repeatability of 2 m/s. This error, for the axial mean velocity, was of the same order as was produced by using a different calibration from the same day. PDV RMS velocities exhibited a repeatability of 0.5--1.0 m/s, and generally are about one half as large as the hot wire anemometer RMS velocities."]},{"key":"dc:title","label":"Title","values":["Point Doppler velocimetry measurements in circular jets"]}]}],"canonical_facts":{"dc:contributor":["John M. Kuhlman."],"dc:creator":["Collins, Patrick Michael"],"dc:date.available":["2019-01-17T08:00:00Z"],"dc:description.abstract":["Improvements have been made to an existing 2-component Point Doppler Velocimetry (PDV) system to improve instrument accuracy and repeatability and to reduce mean velocity offset. Most importantly, the original iodine cells have been replaced by vapor-limited iodine cells that are not influenced by room temperature variations. PDV is a non-intrusive laser based flow measurement technique with capabilities that are similar to hot wire anemometry, but without inserting a probe into the flow. The insertion of a probe into a flow can affect the flow, resulting in inaccurate measurements.;PDV measurements for 1 inch diameter standard, swirling, and annular jets have been made at a nominal exit velocity of 60 m/s, corresponding to a Reynolds number of 100,000. Measurements of radial profiles of mean and RMS velocities were taken for each jet from the jet exit to X/D=12 at nine different X locations. Also, centerline velocity profiles were taken from the jet exit to X/D=12. Comparisons between hot wire anemometry and PDV measurements have been made for standard and swirling jets, and PDV data repeatability has been judged by multiple runs for each jet.;Hot wire anemometry measurements in the swirling jet appear to be inaccurate for X/D ≤ 4 due to the inability of the hot wire anemometer to accurately measure two-dimensional flow velocities. The PDV and hot wire comparisons for the standard jet have good correlation for the mean velocity; however, the RMS velocities do not agree. PDV measurements of the axial and circumferential mean velocities exhibited an uncertainty and repeatability of 2 m/s. This error, for the axial mean velocity, was of the same order as was produced by using a different calibration from the same day. PDV RMS velocities exhibited a repeatability of 0.5--1.0 m/s, and generally are about one half as large as the hot wire anemometer RMS velocities."],"dc:identifier":["https://doi.org/10.33915/etd.1015","https://researchrepository.wvu.edu/etd/1015"],"dc:subject":["Mechanical engineering","Aerospace engineering"],"dc:title":["Point Doppler velocimetry measurements in circular jets"],"thesis:degree_discipline":["Mechanical and Aerospace Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["MS"]},"updated_at":"2026-07-24T06:15:08Z"}