Design and Uncertainty Analysis of a Second-Generation Convective Heat Flux Calibration Facility
David G. Holmberg, C A. Womeldorf, William L. Grosshandler
The National Institute of Standards nad Technology has developed a convective heat flux facility to allow calibration of heat flux sensors. The facility consists of a small wind tunnel that produces a two-dimensional laminar boundary layer across a heatred isothermal copper plate. Sensors are mountd flush in the copper plate alongside a reference to measure the heat leaving the plate. Convective calibrations up to 5 kW/m2 are possible. Sensor output is compared with the reference value, and contrasted with a standard radiation calibration. Recognizing that many sensors are used in mixed radiation and convection environment, this facility provides a unique opportunity to assess a sensor's convective response. This report describes a second-generation heated plate and provides an analysis of the system uncertainty. Redundand references, imnproved sensor heating and mounting, improved reference isolation, and a minimized radiation component has reduced the combined relative expanded uncertainty of the reference to +2.5%. The benefits of an embedded temperature sensor in the heat flux sensor are described. The facility is available for comparative calibrations and for heat transfer studies by indivdual researchers.
, Womeldorf, C.
and Grosshandler, W.
Design and Uncertainty Analysis of a Second-Generation Convective Heat Flux Calibration Facility, Other, National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=910701
(Accessed May 14, 2021)