CRM Solutions, Inc. maintains a comprehensive knowledge of wind tunnel testing, computational Fluid Dynamics and engineering analyses that allow it to provide a unique capability to supply aerodynamic databases critical to program success. Personnel have over 16 years experience in the analysis of wind tunnel test data and the generation of aerodynamic databases for vehicle flight simulation. This experience includes onsite test support at numerous wind tunnel facilities as well as experience in the planning stages of wind tunnel tests. This background provides a key ingredient to providing databases in an efficient, timely manner and that provide the highest benefit to the project. Personnel have specific experience in the generation of ARES I, ARES I-X and SLS aerodynamic databases in support of full stack, protuberance air loads, reentry trajectory calculation, parachute recovery load determination, and range safety analyses. Typical users of databases are range safety, loads, guidance, navigation and control (GN&C), and flight simulation. These databases are essential to mission success and are the first databases of their kind produced since early in the Space Shuttle program. The complex and unique aerodynamic flight regime of reentry is one in which the CRM team has unique knowledge.
In addition, team members have experience in testing and generating aerodynamic databases for Ares I and SLS ascent phases of flight, as well as numerous missile configurations for Department of Defense customers. The team is also knowledgeable in engineering analysis codes and tools to enable either supplementation of wind tunnel test data or verification testing of results obtained. This experience ensures that database products will accurately reflect the real world flow phenomena of the flight vehicle and provide the most accurate aerodynamic representation of the vehicle for trajectory and other simulation uses. Team members possess the skills necessary to assemble data from multiple analyses into a unified product of relevant use to the program. This ability lowers risk and provides a more accurate and useful database product. In addition, team members possess a working knowledge of the reentry simulation codes for which the databases are generated. This knowledge allows team members to design databases from the start that meet all simulation requirements as well as provide database products that more seamlessly integrate with existing simulation tools.
A database product for which CRM has developed a innovative process is for protuberance air loads, which can be an extremely complex and manpower intensive task. CRM produced the protuberance air loads database for the NASA Ares vehicle and currently provides this data for the NASA Space Launch System. Accurate knowledge of the protuberance loads is important for a number of reasons, including determining the size and spacing of fasteners, skin thicknesses, and underlying support structure. CRM Solutions working with NASA structural and aerodynamic engineers developed a novel approach for post processing CFD solutions to give structural and venting engineers the necessary information to perform structural loads analysis on vehicle protuberances. In our approach (see “CFD PUBS” tab), the protuberances are divided into patches which make sense from a structural point of view. The aerodynamic loads are integrated on the patches and the minimum and maximum forces on each patch over the CFD matrix are provided to the structural engineer. The SLS vehicle contains 140 major protuberances. The CFD matrix (performed by NASA Ames) contains 739 simulations. From the CFD solutions over 600,000 files (approximately two terabytes) of data were extracted. From the CFD extracted files the CRM protuberance air loads utilities generate over 1.5 million intermediate files. The final result of the PAL database is 280 simple excel spread sheets (2 per protuberance) which give the minimum and maximum loads on the protuberance and sectional loads/load distribution plots to visually examine load concentrations on the protuberances.
The gallery below provides examples from varying databases produced at CRM with in-house computing.
Space Launch System (SLS) Aborted Stack Database
SLS Sectional Loads Database
One of 140 SLS Protuberances in the Loads Database
Ares Core Stage Re-Entry Database
Ares Aborted Stack Database
Ares Core Stage Re-Entry Database
Ares Upper Stage Force/Moment Database