59622 - Educational Effectiveness of Brayton Cycle Compare and Solve Interactive Gas Turbine Simulator 

The air-breathing Brayton cycle is widespread throughout power generation and propulsion systems, making it a fundamental part of every mechanical or aerospace engineering student’s repertoire. Students are introduced to cycle analysis in thermodynamics courses and may see more in-depth coverage of the cycle for gas turbine applications in advanced technical elective courses. When pushing students from analyzing to designing an engine, they need to immediately see the effects of any change they make. In addition, students need to be able to compare their engine designs and make sense of the effects their changes have on the overall engine performance. The solution to enable this kind of design work in a course is a lightweight cycle simulator tool capable of quickly and accurately analyzing Brayton cycle engines.  For the tool to be useful in a classroom, it needs to be intuitive, easy to use, and quick to set up, so no time is wasted learning the software. Users with an introductory background of the non-ideal Brayton cycle should be able to open the program and immediately start analyzing the cycle of a relevant engine. 

These requirements are met in the creation of a gas turbine engine simulator, Brayton Cycle: Compare & Solve (BCCS). In a Matlab graphical user interface, that can be hosted on a web page, the user specifies numerous engine parameters such as: component efficiencies, stage pressure ratios, flight speeds, engine layouts, etc. Next, the tool performs complete thermodynamic design point analysis of the engine. From here, the user can generate temperature-entropy and pressure-volume diagrams, view the fluid properties at each station, and view engine performance parameters such as net thrust or thrust specific fuel consumption. Most importantly, the solver records the results so multiple engines can be solved and compared simultaneously. Users can make small changes to an engine and instantly see how their changes affect the engine temperatures, pressures, and performance. Being able to analyze and compare engines quickly enables the introduction of more design-based problems.

This paper discusses three topics. First, a review of the currently available engine simulation tools is discussed, with a focus on the capabilities of each program and how a student might use them in an undergraduate course. Through this review, it becomes apparent there is an open niche for a simple-to-use solver that compares engines, which BCCS fills. The second topic is the operation of BCCS and the analysis process it uses. The final topic is how BCCS can be leveraged to enhance design-based learning, specifically in an existing aerospace engineering propulsion course at The Ohio State University. This includes lecture methods, homework problems, evaluation of the experience using the Student Response to Instructional Practices tool, and assessment of student learning outcomes.