Hotpac

Abstract

This report presents and discusses a number of recent developments in the steady-state thermal analysis of multiple-layer structures. These include: 1) analytical evaluation of line and area average temperatures and 2) a recursion relation technique for calculating the steady-state surface temperature of a multilayer structure with an arbitrary number of layers. The application of the analytic averaging to the TXYZ code is incorporated in the updated code, TXYZ30, while the multilayer recursion relation solution along with analytic averaging are included in the Thermal MultiLayer code, TML. Both of these are contained in the HOTPAC software package. The first part of this report contains a discussion of the general elements of the multiplelayer thermal model. This is presented in some detail for the case of the Kokkas three-layer problem and the associated TXYZ code. The previous update of the code, TXYZ20, is also discussed. This incorporates more flexible handling of input data, assignment of positive or negative noninteger weights to the various heat sources or heat sinks, and improved evaluation of limiting forms in the code. The second part of the report presents the analytical evaluation of line and area averages which can be calculated directly. The analytical calculation of the area average temperature should provide for a more direct and convenient connection to the experimentally measured temperature which tends to average over the measurement area. The line and area averaging are incorporated into the TXYZ code to produce the TXYZ30 update. The third portion contains a detailed discussion of the calculation of the surface temperature of a multilayer structure with an arbitrary number of layers. This is based on a recursion relation technique previously employed in electrical spreading resistance analysis to determine the surface potential from the multilayer electrical Laplace equation. The line and area averaging techniques can be applied directly to the recursion relation solution and are included in the Thermal MultiLayer, TML, code. The appendices contain the listing of the annotated, internally documented FORTRAN source codes for TXYZ30 and TML. These codes as well as several sample input and output data files are available in ASCII format on DOS-formatted floppy disks. The sample input and output data files are included so that the user can check the programs for proper operation as well as become familiar with the setup and use of the codes. Users of the 1 previous versions of the TXYZ code should find the TXYZ30 and TML codes easy to use and should benefit from the wider range of problems which they can be used to address.

Convective‐scale assimilation of radar data: progress and challenges

“…An approach that has been used in a number of high-resolution data assimilation systems is to assimilate radar data at a different step in which an analysis obtained by assimilating all other data types is used as a background. In the LAPS wind analysis, radar wind is analysed in the second pass using the same successive-correction technique but a different weighting function (Albers 1995). Crook and Sun (2002) described a technique in which a mesoscale analysis and a convective-scale analysis were performed using different techniques.…”

“…In the LAPS wind analysis, radar wind is analysed in the second pass using the same successive-correction technique but a different weighting function (Albers 1995). Crook and Sun (2002) described a technique in which a mesoscale analysis and a convective-scale analysis were performed using different techniques.…”

“…Bratseth (1986) showed that a successivecorrection scheme could converge to the Optimal Interpolation (OI) solution. The Local Analysis and Prediction System (LAPS) of NOAA's Forecast System Laboratory applies the successive-correction method in their high-resolution analysis and includes Doppler radar observations (Albers 1995). Radar radial velocity and reflectivity observations are mapped to the analysis grid prior to the assimilation.…”