A Brief History of SINDA/FLUINT
SINDA/FLUINT is the culmination of thermal/fluids software development dating back to the 1960's when the CINDA code was developed by Chrysler Aerospace. TRW revised the code for NASA in 1972 and renamed it to SINDA, a precursor to several subsequent codes including Hughes' CINDA (or HSCINDA), MITAS, and SINDA/G.
In 1982 the NASA/TRW version and MITAS versions were used as starting points for SINDA/FLUINT (then called SINDA '85 or SINDA-85, corresponding to its first release date). In 1986 the fluid module, FLUINT, was first released, greatly expanding the code and making it one of the first co-solved heat transfer and fluids analysis software products. SINDA/FLUINT was well received and has successfully supplanted other SINDA versions and SINDA-like codes, becoming a best-seller and a NASA Space Act Award winner (1991) in the process. NASA continued to guide the development of SINDA/FLUINT until 1992 when the code was identified for commercialization by CRTech. Subsequent improvements over older SINDA codes include submodels, registers and expressions (an underlying spreadsheet), design optimization and test data correlation, statistical design methods, and a comprehensive fluid flow analysis capability.
Originally intended to satisfy the ever-changing modeling needs of the spacecraft and launch vehicle thermal community, SINDA/FLUINT has diffused into other industries such as aircraft, electronic packaging, HVAC, automotive, medical, petrochemical, energy and into other specialties and subsystems such as cryogenic and environmental control. SINDA/FLUINT is intended primarily for designing and analyzing thermal and fluid systems represented in electrical analog, lumped parameter form. Given properly prepared inputs, SINDA can also solve both finite difference and finite element equations: it is better classified as an "equation solver" than its traditional classification as a "finite difference solver."
SINDA/FLUINT is now arguably the most advanced one dimensional thermal/fluids software available in today's market, solving arbitrary fluid flow networks without presuming the application. The networks may contain single-phase vapor or liquid as the working fluid, or combinations of liquid and/or vapor at various locations in the network, and even mixtures of reacting or non-reacting working fluids. These networks are solved in conjunction with one or more accompanying thermal networks, accounting for the energy flows in and out of the fluid system(s).
The improvements that yield the most analytic power, however, are hidden ... or at least external to SINDA/FLUINT. Until the 1990's, SINDA/FLUINT was primarily used as a batch style code run with manually-generated text input files, although archaic codes such as TRASYS were often used to prepare certain inputs such as radiation factors. Now, thanks to a new generation of graphical interfaces, SINDA/FLUINT is primarily used as a "solution engine." These interfaces include the geometry-based Thermal Desktop® (for SINDA conduction/capacitance calculations) with its companion modules RadCAD® (SINDA radiation calculations) and FloCAD® (FLUINT circuits and convective heat transfer calculations).
The integration with FloCAD, which offers both geometric and non-geometric schematic-style modeling, has significantly improved the ease of use for fluid modeling. These unique hybrid 1D+3D features in FloCAD enabled the deprecation of older but popular sketchpad-only interfaces called Sinaps® and SinapsPlus®. The final version of Sinaps featured an automatic model converter into Thermal Desktop and FloCAD format.
