OPTIMISATION OF THE REDUCTION OF TRANSIENT HEAT TRANSFER DATA,
Abstract
In many cases an unknown function is approximated by a number of observations and the slope is needed. This is often done by fitting a polynomial through a group of the points using the least square method. In the present paper, the error introduced into the slope is determined for some cases which are representative for experiments using the transient heat transfer technique. The results can either be used when new experiments are planned or when the best combination of parameters (number of points approximated by the polynomial, degree of polynomial) has to be determined for the reduction of existing data. It is found that, within the framework of assumptions made, a second degree polynomial gives exactly the same slope as one with a first degree. The same is true for the third and fourth degree, fifth and sixth degree etc. Therefore, polynomials with an even degree should not be used in this connection as they do not improve the accuracy of the result. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- AD0687166
Entities
People
- G. Lindsjo
- H. Thomann
Organizations
- National Aeronautical Research Institute