Abstract:

This work presents a practical application using a spreadsheet to evaluate the open thermodynamic cycle of a laboratory micro-jet engine. A previously developed spreadsheet was adapted to assess several engine models available in the Thermal Engineering laboratory at the University of Jaén (e.g., JetCat 120P, JetCat 100RX, Olympus HP). All models share a common approach based on a compressor map defined in terms of non-dimensional mass flow rate. Additionally, the spreadsheet is generic and can be applied to different turbine configurations, allowing versatility for various laboratory applications.

Following experimental measurements at a given engine load—including rotational speed, volumetric fuel flow rate, thrust, and exhaust gas temperature—the analysis begins with the evaluation of compressor behavior using dimensional analysis, from which the remaining components of the cycle are evaluated (compressor, combustion chamber, turbine, and nozzle).

This procedure is applied in a laboratory activity of the course Thermal Machines in the Bachelor’s Degree in Mechanical Engineering at the University of Jaén. The exercises are completed individually under instructor guidance, promoting active learning, hands-on experimentation, and problem-solving skills. Students report a highly positive experience, highlighting the instructor’s support throughout the exercises, which promotes motivation, reinforces conceptual understanding, and strengthens practical problem-solving abilities.

Keywords:

Engineering Education, Active Learning, Microjet Engine, Spreadsheet-Based Learning Tool, Open Thermodynamic Cycle, Laboratory Practice.