Refining Flow Characterization Desk-Scale Experiments and Blended Learning in Engineering Education: A Framework for Assessment

Abstract Pump and valve characterization is of utmost relevance when designing flow systems, thereby ensuring optimal pump performance, validating valve compliance with technical and safety requirements, and facilitating the scalability of processes. The empirical exploration of pump and valve characterization is common in laboratory practices within mechanical and civil engineering curricula. However, it has experienced a declining presence in chemical engineering majors and remains notably scarce in other diverse disciplines such as agricultural, food, and biomedical engineering. These disciplines may find graphical flow characterizations significant in the delineation of processes across a spectrum of applications. Aiming to enhance students' experiential learning in diverse engineering disciplines, we propose a straightforward approach for conducting experiments related to pump and valve characterization using a cost-effective and adaptable desk-scale experimental setup. The flow system comprises several components, including a plastic feed tank, aquarium pumps (either centrifugal or diaphragm), valves (pinch or needle), flexible tubing, 3D-printed pressure taps, and a differential pressure sensor connected to a laptop via Arduino microprocessor. During these experiments, measurements such as pressure drop and flow rates across pumps and valves are collected. These measurements allow students to construct characteristic curves for various types of pumps and valves. The analysis can be extended to assess the net positive suction head, investigate cavitation safely, and develop predictive system curves. Furthermore, the experimental setup allows for easy configuration of pumps in series or parallel arrays, broadening the range of experiments beyond traditional characteristic curves. Due to the compact nature of the experimental setup, only a small desk space is required thus rendering it suitable for implementation in either classroom or laboratory environments. Additionally, required materials can be procured from local hardware stores or e-commerce platforms. Experiments are characterized by their inherent safety, relying on tap water at room temperature. Because of the adaptability of these experiments, they can be tailored to cater to a wide array of engineering disciplines. This adaptability extends to the level of complexity within experiments and the subsequent data analysis, hence accommodating the distinct learning objectives of both lecture and laboratory courses. Furthermore, experiments can be used for online education. Materials can be shipped to students along with didactic materials, and the course can be delivered synchronously or asynchronously thus making this approach a versatile tool for remote learning. These desk-scale experiments have been incorporated into a junior chemical engineering laboratory either alone or in combination with pilot-scale experimentation. Preliminary feedback from students has shown promising potential, suggesting that desk-scale experimentation improves the interpretation of flow characteristic curves, allowing for experimental versatility. Efforts are currently underway to optimize these experiments thus making them well-suited option for educational programs facing resource limitations, such as insufficient laboratory space, constrained budgets for laboratory equipment, accommodations for students with disabilities, or curricular constraints that may hinder traditional experimental activities. By providing a cost-effective, adaptable, and safe alternative, we aim to expand access to hands-on learning experiences, bridging gaps and enriching the educational journey for students of various engineering disciplines.