{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/51422"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/51422","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Experimental Investigation of Dimples as a Heat Transfer Enhancement Feature in Narrow Diverging and Converging Channels","abstract":"Detailed heat transfer coefficient distributions have been obtained for narrow converging and diverging channels with and without enhancement features. The enhancement feature considered for this study is dimples (inline and staggered) on the main heat transfer surfaces. All the measurements are presented at Reynolds numbers of 3500, 8900, 18000, and 7000, 14000, 28000 for converging and diverging channels respectively. Pressure drop measurements for the overall channel are also presented to evaluate the heat transfer enhancement geometry with respect to pumping power requirements. The test models were studied for wall heat transfer coefficient measurements using the transient liquid crystal technique. The modeled wall inner surfaces were sprayed with thermochromic liquid crystals, and a transient test was used to obtain the local heat transfer coefficients from the measured color change. Analysis of results shows that dimples, in general, have very good enhancement capabilities and staggered dimpled surfaces provide considerably higher heat transfer coefficients and a reasonable pressure drop compared to inline dimpled configuration. Additionally, this study was extended to understand the effect of strategic placement of dimples (staggered) at various locations along the channel to understand regions that contribute significantly to the overall enhancement.","abstract_html":"Detailed heat transfer coefficient distributions have been obtained for narrow converging and diverging channels with and without enhancement features. The enhancement feature considered for this study is dimples (inline and staggered) on the main heat transfer surfaces. All the measurements are presented at Reynolds numbers of 3500, 8900, 18000, and 7000, 14000, 28000 for converging and diverging channels respectively. Pressure drop measurements for the overall channel are also presented to evaluate the heat transfer enhancement geometry with respect to pumping power requirements. The test models were studied for wall heat transfer coefficient measurements using the transient liquid crystal technique. The modeled wall inner surfaces were sprayed with thermochromic liquid crystals, and a transient test was used to obtain the local heat transfer coefficients from the measured color change. Analysis of results shows that dimples, in general, have very good enhancement capabilities and staggered dimpled surfaces provide considerably higher heat transfer coefficients and a reasonable pressure drop compared to inline dimpled configuration. Additionally, this study was extended to understand the effect of strategic placement of dimples (staggered) at various locations along the channel to understand regions that contribute significantly to the overall enhancement.","abstract_has_math":false,"creators":["Srinivasan, Shreyas"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mechanical Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Ekkad, Srinath V."],"committee_members":["Tafti, Danesh K.","Ma, Lin"],"year":2013,"date_issued":"2013-08-22","date_published":"2013-08-22","updated_at":"2026-07-22T22:19:51Z","subjects":["Heat transfer","Narrow channels","Dimples","Heat transfer enhancements."],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:1531"],"render_values":[{"text":"vt_gsexam:1531","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/51422","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Ekkad, Srinath V."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Tafti, Danesh K.","Ma, Lin"]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Srinivasan, Shreyas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2015-02-14T07:00:06Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2015-02-14T07:00:06Z"]},{"key":"dc:date.issued","label":"Date","values":["2013-08-22"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Heat transfer","Narrow channels","Dimples","Heat transfer enhancements."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:1531"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/51422"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Detailed heat transfer coefficient distributions have been obtained for narrow converging and diverging channels with and without enhancement features. The enhancement feature considered for this study is dimples (inline and staggered) on the main heat transfer surfaces. All the measurements are presented at Reynolds numbers of 3500, 8900, 18000, and 7000, 14000, 28000 for converging and diverging channels respectively. Pressure drop measurements for the overall channel are also presented to evaluate the heat transfer enhancement geometry with respect to pumping power requirements. The test models were studied for wall heat transfer coefficient measurements using the transient liquid crystal technique. The modeled wall inner surfaces were sprayed with thermochromic liquid crystals, and a transient test was used to obtain the local heat transfer coefficients from the measured color change. Analysis of results shows that dimples, in general, have very good enhancement capabilities and staggered dimpled surfaces provide considerably higher heat transfer coefficients and a reasonable pressure drop compared to inline dimpled configuration. Additionally, this study was extended to understand the effect of strategic placement of dimples (staggered) at various locations along the channel to understand regions that contribute significantly to the overall enhancement."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Experimental Investigation of Dimples as a Heat Transfer Enhancement Feature in Narrow Diverging and Converging Channels"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Ekkad, Srinath V."],"dc:contributor.committeemember":["Tafti, Danesh K.","Ma, Lin"],"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Srinivasan, Shreyas"],"dc:date.accessioned":["2015-02-14T07:00:06Z"],"dc:date.available":["2015-02-14T07:00:06Z"],"dc:date.issued":["2013-08-22"],"dc:description.abstract":["Detailed heat transfer coefficient distributions have been obtained for narrow converging and diverging channels with and without enhancement features. The enhancement feature considered for this study is dimples (inline and staggered) on the main heat transfer surfaces. All the measurements are presented at Reynolds numbers of 3500, 8900, 18000, and 7000, 14000, 28000 for converging and diverging channels respectively. Pressure drop measurements for the overall channel are also presented to evaluate the heat transfer enhancement geometry with respect to pumping power requirements. The test models were studied for wall heat transfer coefficient measurements using the transient liquid crystal technique. The modeled wall inner surfaces were sprayed with thermochromic liquid crystals, and a transient test was used to obtain the local heat transfer coefficients from the measured color change. Analysis of results shows that dimples, in general, have very good enhancement capabilities and staggered dimpled surfaces provide considerably higher heat transfer coefficients and a reasonable pressure drop compared to inline dimpled configuration. Additionally, this study was extended to understand the effect of strategic placement of dimples (staggered) at various locations along the channel to understand regions that contribute significantly to the overall enhancement."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:1531"],"dc:identifier.uri":["http://hdl.handle.net/10919/51422"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Heat transfer","Narrow channels","Dimples","Heat transfer enhancements."],"dc:title":["Experimental Investigation of Dimples as a Heat Transfer Enhancement Feature in Narrow Diverging and Converging Channels"],"dc:type":["Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:51Z"}