Method and apparatus for measuring local heat transfer distribution on a surface
AssigneeGeneral Electric Company
InventorsLamyaa Abdel Alle El-Gabry, Steven J. Brzozowski, Nirm V. Nirmalan
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Abstract
An apparatus and method for measuring local heat transfer distribution of an object surface. The apparatus includes a heater element for providing heat flux, a member disposed on a surface of the heater element for receiving impinging cooling air. A liquid crystal element is provided on a side of the heater element remote from the surface, and an insulating material is disposed adjacent to the liquid crystal element and remote from the heater element. The apparatus further includes means for determining heat transfer distribution coefficients from the liquid crystal element.
Claims23
A method of measuring local heat transfer characteristics of an object surface, the method comprising the steps of:
- (a) flowing a cooling medium onto the surface;
- (b) sensing the temperature of the surface by juxtaposing a broadband width liquid crystal sheet and the surface;
- (c) measuring temperature distributions of each pixel of the liquid crystal sheet at various heat flux levels;
- (d) processing the temperature distributions to obtain temperature distribution profiles at each heat flux level;
- (e) determining heat transfer coefficients of each pixel at each heat flux level
- (f) determining an average heat transfer coefficient profile at each pixel;
- and
- (g) performing steps (a), (b) and (c) at steady state conditions.
In an apparatus comprising a heater element and a liquid crystal sheet juxtaposed in temperature sensing relation to an object surface, a method of measuring local heat transfer distribution along the surface comprising the steps of:
- (a) directing a cooling gas through a plurality of openings forming plural jets of cooling air impinging on the object surface;
- (b) obtaining steady state images of said liquid crystal sheet as a function of the sensed temperature of the cooled object surface at various heat flux levels;
- (c) processing said steady state images to determine temperature distribution profiles at each pixel along said liquid crystal sheet;
- (d) determining heat transfer coefficients for each temperature distribution profile;
- and
- (e) determining an average heat transfer coefficient profile.
A method for measuring local heat transfer distribution of an object surface, the method comprising the steps of:
- (a) directing cooling air through a plurality of openings forming plural jets of cooling air impinging on the object surface;
- (b) providing a liquid crystal sheet on a side of a heater element remote from the object surface;
- (c) energizing said heater element to various heat flux levels;
- (d) measuring temperature distributions of various pixels of said liquid crystal sheet at the various heat flux levels;
- (e) processing said temperature distributions to obtain temperature distribution profiles;
- and
- (f) obtaining heat transfer coefficients for each distribution profile.
An apparatus for measuring local heat transfer distribution of an object surface, comprising:
- a heater element for providing heat flux;
- a test plate disposed on a surface of the heater element for receiving impinging cooling air;
- a liquid crystal sheet on a side of said heater element remote from said surface;
- an insulating material in contact with said liquid crystal sheet and remote from said heater element;
- and
- means for determining heat transfer coefficients distribution from said liquid crystal sheet.
An apparatus for measuring local heat transfer distribution of an object surface, comprising:
- a liquid crystal sheet;
- a heater element for heating the liquid crystal sheet to various heat flux levels;
- said liquid crystal sheet disposed adjacent to the heater element for measuring heat transfer distributions of the object surface;
- means for capturing images of said liquid crystal sheet at each heat flux level;
- and
- means for determining heat transfer coefficients from the captured images.
An apparatus for measuring local heat transfer characteristics of an object surface, comprising:
- means for flowing a cooling medium onto the surface;
- means for heating and sensing the temperature of the heated surface by juxtaposing a broadband liquid crystal sheet and the surface;
- means for measuring temperature distributions of each pixel of the liquid crystal element at various heat flux levels and at steady state conditions;
- means for processing the temperature distributions to obtain temperature distribution profiles at each heat flux level;
- means for determining heat transfer coefficients of each pixel at each heat flux level;
- and
- means for determining an average heat transfer coefficient profile at each pixel.
Dependencies are inferred from the claim text.