Cryogenic Systems Integration Model (CSIM)

The Cryogenic Systems Integration Model (CSIM) is a Microsoft Windows(R) 95 based software tool for the simulation and analysis of spacecraft cryogenic mechanical refrigeration thermal control systems. Previous experience has shown that cryogenic systems exhibit large analytical uncertainties. Historically, cryogenic thermal integration has been critical and often inadequately considered during the preliminary design phase resulting in significant revisions and system penalties. CSIM development was initiated in response to the need for an efficient method for the preliminary design and parametric analysis of spacecraft cryogenic mechanical refrigeration systems. CSIM provides the capability to model and simulate the thermal performance of a cryogenic mechanical refrigeration system consisting of instruments, cryocoolers, thermal straps, thermal storage units, thermal switches, heat pipes, intermediate shields, radiators, and brackets. The simulation outputs provide a complete breakdown of temperatures, heat flows, dimensions, weight, power, and total system penalties. Version 2.1 was presented at the 9th International Cryocooler Conference (ICC9). An updated and improved version (3.0-030) is presented in this paper. Enhancements include: a) the addition of a context sensitive help system, b) a Carnot correction and stroke interpolation routine which allows the user to interpolate or extrapolate the cooler performance to a heat rejection temperature and stroke (or power level) different from that provided in the database, c) revisions and improvements to the network display and dialog boxes to make the program easier to use, and d) expansion of the cooler database which includes incorporation of several coolers characterized at the Air Force Research Laboratory (AFRL), Albuquerque, New Mexico, during the last few years. The program has been licensed to a number of aerospace industry contractors and government agencies and is available to qualified users.