<p dir="ltr">This thesis details the development of a multidisciplinary design analysis (MDA) framework intended to evaluate a rocket-powered, reusable hypersonic vehicle. In particular, the analysis framework computes the design closure of a coupled system resembling Stratolaunch Systems’ Talon-A reusable hypersonic test vehicle. The resulting analysis framework differs from available literature due to its focus upon payload-related design considerations. The presented framework, too, avoids the use of proprietary technical information and/or export-controlled analysis tools. The framework’s geometric analysis, for example, employs a reverse-engineered geometry resembling Talon-A. An open-source aerothermal package, too, was selected to evaluate the vehicle’s aerothermodynamic characteristics. Quick-to-implement methods were prioritized to expedite the development of the MDA framework. Notably, a regression-based structural analysis model was used, as well as an interpolative thermal protection system (TPS) sizing procedure. A quasi-steady trajectory model, too, was implemented within the MDA framework, to determine the vehicle’s mission performance. The resulting analysis takes the form of a six-discipline MDA framework that can calculate, among other parameters, the vehicle’s cruise duration. Initial design closure results for a vehicle resembling Talon-A, using an assumed TPS size, are currently available. These results report an estimated total vehicle mass within thirty percent of Talon-A’s true gross mass, as well as a cruise duration of approximately 445 seconds. These design closure results were also evaluated under a perturbed specific impulse of ±10%, with a resulting change in cruise duration of ±12.3%. Results for a cruise-condition design exploration procedure were also obtained within a simplified, sequential analysis chain. These design exploration results report a maximum cruise lift-to-drag ratio of approximately four. Future work has been identified, too, including the integration of more rigorous analysis tools for use within future iterations of the MDA framework. Notably, these tools include an open-source optimal control library, as well as a physics-based TPS sizing tool</p>

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A formal framework is developed and implemented in this research for preliminary rotorcraft design using IPPD methodology. All the technical aspects of design are considered including the vehicle engineering, dynamic analysis, stability and control, aerodynamic performance, propulsion, transmission design, weight and balance, noise analysis and economic analysis. The design loop starts with a detailed analysis of requirements. A baseline is selected and upgrade targets are identified depending on the mission requirements. An Overall Evaluation Criterion (OEC) is developed that is used to measure the goodness of the design or to compare the design with competitors. The requirements analysis and baseline upgrade targets lead to the initial sizing and performance estimation of the new design. The digital information is then passed to disciplinary experts. This is where the detailed disciplinary analyses are performed. Information is transferred from one discipline to another as the design loop is iterated. To coordinate all the disciplines in the product development cycle, Multidisciplinary Design Optimization (MDO) techniques e.g. All At Once (AAO) and Collaborative Optimization (CO) are suggested. The methodology is implemented on a Light Turbine Training Helicopter (LTTH) design. Detailed disciplinary analyses are integrated through a common platform for efficient and centralized transfer of design information from one discipline to another in a collaborative manner. Several disciplinary and system level optimization problems are solved. After all the constraints of a multidisciplinary problem have been satisfied and an optimal design has been obtained, it is compared with the initial baseline, using the earlier developed OEC, to measure the level of improvement achieved. Finally a digital preliminary design is proposed. The proposed design methodology provides an automated design framework, facilitates parallel design by removing disciplinary interdependency, current and updated information is made available to all disciplines at all times of the design through a central collaborative repository, overall design time is reduced and an optimized design is achieved.