Measurements of heat transfer coefficients for jet impingement array using thermo chromic liquid crystal (TLC) technique
Dissertant
University
University of Technology
Faculty
-
Department
Department of Electromechanical Engineering
University Country
Iraq
Degree
Master
Degree Date
2009
English Abstract
Spatial heat transfer coefficients distribution measurements have been made using thermochromie liquid crystal technique for several cases of normally impinging air jet arrays onto a flat, smooth surface within a three sides closed channel.
The study investigated the effect of the number of jets, and jet-to-target plate spacing (Z/D), for the target plate in the presence of a cross flow originating from upstream jets on the heat transfer distribution of jets' target plate.
Two-dimensional inline anays of circular jets of air impinging on a heat transfer surface parallel to the jet-issuing plate were considered.
The air, after impingement, was constrained to exit in a single direction along a channel formed by the target plate, the jet-issuing plate and the spacers, The downstream jets were subjected to a cross flow from the upstream jets.
Jet distribution was tested according to 3 sets : 3 rows with 3 holes in each row, 5 rows with 5 holes in each row, and 7 rows with 7 holes in each row.
The jet-to-jet spacing X/D for all jet plates was 2, 3, and 4 holes in diameter in the span wise direction and the same in the stream wise direction.
Tests were conducted at a Reynolds number between 121 and 751.
The heat transfer measurement used a liquid crystal imaging technique with a one-dimensional transient conduction model.
The impingement heat transfer results are correlated in terms of the non-dimensional parameters ; Reynolds number (Re), X at constant jet whole diameter (X / D) and gap height at constant jet diameter (Z / D), the following correlation was obtained.
The measurement system was verified by comparing against well-known data sets of heat transfer measurement, Kerchief and Tabak off (1970) [S4], for a simplified model, a 49~hole target plate (X / D = 2), the discrepancy from the current measurement system has been found to be no more than 5%.
An optimum distance for jet-to-target plate spacing was found to be Z / D = 0.5 for the 9-hole case (X / D = 4), the 25-hole case (X / D = 3) is Z/D=3t and for the 49-hule case (X/ D = 2) is Z / D = 3.
Main Subjects
Topics
American Psychological Association (APA)
al-Qaysi, Khalid A. S.. (2009). Measurements of heat transfer coefficients for jet impingement array using thermo chromic liquid crystal (TLC) technique. (Master's theses Theses and Dissertations Master). University of Technology, Iraq
https://search.emarefa.net/detail/BIM-304957
Modern Language Association (MLA)
al-Qaysi, Khalid A. S.. Measurements of heat transfer coefficients for jet impingement array using thermo chromic liquid crystal (TLC) technique. (Master's theses Theses and Dissertations Master). University of Technology. (2009).
https://search.emarefa.net/detail/BIM-304957
American Medical Association (AMA)
al-Qaysi, Khalid A. S.. (2009). Measurements of heat transfer coefficients for jet impingement array using thermo chromic liquid crystal (TLC) technique. (Master's theses Theses and Dissertations Master). University of Technology, Iraq
https://search.emarefa.net/detail/BIM-304957
Language
English
Data Type
Arab Theses
Record ID
BIM-304957