The multiphase results from this work and new computational capabilities will give a more complete picture of the extreme conditions the launch environment experiences and will help NASA reduce mission risk-increasing safety and potentially saving significant amounts of time and money. By refining the model of the launch environment to include the water effects from the sound suppression system, a more accurate prediction of loads on the vehicle, mobile launcher, tower structures, and flame trench was achieved. Additionally, the team is using the validated solver to provide ignition overpressure protection estimations for the SLS at LC-39B. The numerical and experimental signals demonstrated excellent agreement. The LAVA team performed simulations of the SMAT and compared mean pressure signals at many sensor locations. This effort has been extended and tasked by the NASA Engineering and Safety Center (NESC) to reduce simulation turnaround time by improving the scalability of the LAVA multiphase solver for high-performance computing. These simulations required careful preparation due to their complexity, and ultimately the numerical results showed excellent agreement with test data. A milestone of the EGS project was the validation of the new solver against measured test data from the scale test SMAT. The algorithm has been verified using manufactured solutions to demonstrate the correct implementation of the solver and the high-order convergence rate (a detailed description of the mathematical model and the numerical scheme can be found in the paper by Wong, et al.). Starting in 2020, KSC Exploration Ground Systems (EGS) supported the use of LAVA’s multiphase flow simulation capabilities to study the extreme launch environment conditions computationally, including modeling the Scale Model Acoustic Test (SMAT), a 5% scale test meant to represent the Space Launch System (SLS) and Mobile Launcher (ML) at LC-39B. Given a future of increasing NASA and commercial launch missions, the opportunities for a well-validated and robust multiphase CFD tool are numerous. This tool allows for refined predictions of the launch environment, reducing the uncertainty associated with traditional methods. Utilizing this new CFD capability-which is both high-order accurate and provably robust-the LAVA team has been working to demonstrate its ability to make accurate acoustic load predictions. Common semi-empirical methods of estimating loads have built-in conservatism to account for uncertainty, which means that all instruments and vehicles need to be certified for a larger range of vibrations than what might be necessary, leading to excessive increases in weight, cost, schedule, and technical burdens.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |