Design of Hypersonic Lifting Body Vehicle (Lead Chief Engineer’s Report) · Chapter X

AOutcome C: Design System or Process to Meet Needs

The main task for the chief was to derive and define a set of mission requirements from the design intent of the Model 176 to build a mission profile and request deliverables from team members. This required a literature review (see associated chapter) to find which military and market needs were to be addressed, and which vehicle parameters were required to achieve the missions required to address those needs.

To successfully reverse-engineer the Model 176, the author managed the team along a timeline, both near-term (weekly goals) and long-term (entire semester) to complete given tasks. This was determined by both the author and the respective disciplines from their literature search on what the important deliverables were. Towards the beginning, the weekly goals guided the starting activities, but as the semester and disciplines progressed in their literature research, activities began to be dominated by goals determined by disciplinary literature research.

The processes developed by synthesis and the author is outlined in the methodology chapter. It includes a parallel split between the two sub-teams: launch vehicle and hypersonic vehicles. These sub-teams are further split into two parallel processes per sub-team: sizing and disciplinary work. These processes, guided by mission and disciplinary requirements, are compared against the volume and weight budgets tabulated by CAD.

BOutcome D: Ability to Function on Multidisciplinary Teams

The author has taken the responsibility of chief engineer, whose main task is to create and guide the disciplinary activities into a cohesive multi-disciplinary design process. Again, this is demonstrated in the methodology chapter. Following this methodology requires that all team members pull their weight, though that cannot be expected to be the case in the real world. This section as well as the team management chapter describe the lessons learned in dealing with these issues.

Dealing with lapses in performance was first done by example. As should be expected at the very minimum, the chief was never late to a meeting and never skipped a day of class (this was also demonstrated by the supporting chief). In addition to this, the chiefs could not have a lapse in performance, especially since their deliverables were always under the watchful eye of the class faculty head and graduate teaching assistant. The threat of being deposed ensured that the chief position could work effectively and not hold the team back. The unofficial demands imposed on the author has certainly provided the pressure needed to produce a quality product and manage time effectively. This is as much of a learned skill as was the becoming acquainted with the technical aspects.

Secondly, few disciplinary teams worked as a team of one, so that if one member was absent or lagging behind, there was usually a member to pick up the slack. The expectations of a timeline could keep teams on track with their deliverables as well. Attendance was also found to be a determinant of performance, so the author kept track of this per sub-team.

As a last resort, disciplines which failed to provide deliverables were given a grace period, where the author would notify the graduate teaching assistant of a lapse in performance. Fortunately, non-performance did not go past this stage, though time-delays were usually dealt with by the dependent disciplines by using substitute data or methods. There really was no excuse to point fingers at a discipline for not providing deliverables, since all teams proved to be competent in making due with a slow-down.

COutcome F: Understand Professional and Ethical Responsibility

The number one ethical responsibility of an aerospace engineer is to provide a safe design. The two disciplines which are the critical here are structures and stability/control. Their unique analysis is situated at the end of the multi-disciplinary analysis so that they can ensure that the human crew can be safe and stable throughout the flight regime. If there are any dangers posed by the trajectory and aerothermal loads, these disciplines will document their analysis methodology and report results honestly.

Grading and managerial incentives are aligned such that reporting a failure in results is not punished. It is important not to ignore this aspect of the capstone project, as the environment in which the disciplines are expected to perform does have an influence in the daily decisions and reporting of analysis and results. Assumptions are recorded and presented, where historical validation is a requirement for both the reports and the presentation.

Referencing the work of source documents and figures is a base requirement for producing this report. This includes referencing the author’s own works and describing why it is used. The more which is written on the rationale of the author, the more transparent the report is. This transparency is what allows for future preliminary design engineers to go along a path which allows for a working design, as well as to expand on the conceptual analysis under the correct assumptions and methodology.

DOutcome G: Ability to Communicate Effectively

The overall format of this report serves as a communication tool by its hand-made figures, tables, and explanations. The most useful of these, along with those made by other team members, were then put together in the midterm and final presentations. Any figure which is not referenced was constructed by the author to visually communicate key concepts in this project.

One of the goals of the presentation was to provide ample analysis for the specialist, as the flight phase story was told from the relevant disciplines’ perspective. Additionally, by creating the overall presentation according to the order of flight phase, a layman audience and decision maker can follow the mission profile along all three variants. One of the presentation roles of the author was to interject between each flight phase to address the main idea, as well as explain some concepts to the layman. This was heavily aided by presentation visuals, many of which can be found in this report.

EOutcome H: Understand Impact of Engineering Solutions in Global and Societal Context

The entire business case rests on the ability to provide a solution to address global market needs in addition to United States military objectives. Aspects of the business case such as competition analysis acknowledge the wider aerospace industry and their capabilities. Additionally, the market analysis conducted provides a numerical basis for the supposed global need.

The mission profiles and historical context also look into the wider world to guide the team methodology.

FOutcome I: Recognize the Need and Ability to Engage in Lifelong Learning

Much of the literature search completed was done throughout the semester, and as represented by the semester timeline, was continued throughout the summer project. If this is representative of industry, there is certainly a need for lifelong learning.

Hypersonic flight and space vehicle design is not formally taught in the aerospace degree plan, and because of this, team members needed to catch up in their literature search to successfully fulfill deliverables accurately. If the project’s subject had been about helicopters, students would be in the same situation. An engineer’s performance is not only assessed by their knowledge coming into a position, but by their ability to quickly become situated in a specialized set of knowledge they could not possibly have known before entering that position.

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