Gerald Recktenwald

Assessment of student preparedness for freshman engineering courses through assessment of math background

We present an initial investigation of the relationship between math preparedness and student status, and success in freshman electrical and computer engineering courses. We utilize prior math coursework GPA and ALEKS scores as measures of preparedness and find that, with some caveats, they work reasonably well as predictors of success. The majority of our students take freshman engineering courses after completing Calculus 1 or higher. This runs counter to our efforts to engage students in engineering courses first. Students who graduated from high school with some college credit and transfer students with 45-89 transfer credits are susceptible to low grades and high withdrawal rates.

A Simple Experiment to Expose Misconceptions About the Bernoulli Equation

A series of laboratory exercises has been developed to aid in the teaching of thermal and fluid sciences to undergraduate engineers. The exercises use simple hardware and a guided-inquiry approach to expose student misconceptions and to develop deeper understanding of basic concepts. This paper focuses on one of the laboratory exercises, which uses a simple duct with a sudden expansion to demonstrate the error caused by misapplication of the Bernoulli equation. The apparatus and the laboratory exercise are described. Learning gain measurements and results of attitude surveys are presented. The exercise is successful in causing students to confront their misconceptions and lack of understanding. Student attitudes about the usefulness of the exercise correlate with their grade in the course. The A students have a less favorable opinion than the B and C students.Copyright

Guided inquiry laboratory exercises designed to develop qualitative reasoning skills in undergraduate engineering students

We describe inquiry-based lab exercises designed to develop qualitative reasoning skills. The exercises require students to predict outcomes before making measurements, and to compare predictions to measurements as soon as those measurements are available. The predict-then-confirm process aims to develop both qualitative and quantitative reasoning as a practical engineering skill and as a method of gaining deeper understanding of the material. Qualitative reasoning involves the use of engineering models and formulas to draw conclusions without resorting to numerical computation. In this paper, examples of qualitative reasoning are demonstrated for measurements on a kitchen blender and a toaster. Because this equipment familiar to students and has readily understood operating principles, qualitative reasoning can be introduced as a way to extend common sense ideas about how and why the equipment works.

Assessing student preparedness for introductory engineering and programming courses

Our introductory electrical engineering courses still have high attrition rates which raises the question of how to identify students who may be at risk of failing or withdrawing from engineering courses and programs. We have experimented with two different approaches: one is to develop tests that are deployed early in student engineering coursework, and another is to measure student success in prior math courses. Math preparation is the basis of two of the tests, with one also including logic and algorithmic thinking. Preliminary results indicate that purely math-based tests did not correlate well with success in either an introductory problem-solving and programming course, or a sophomore circuits course. A test that includes logic and algorithmic thinking correlated better, but not as well as prior math GPA. All methods currently suffer from large scatter and relatively small correlation factors.

Workshop — Engineering of Everyday Things — Guided inquiry labs

The “Engineering of Everyday Things” is an NSF funded project with the goal of developing a suite of lab exercises for the fluid and thermal sciences. The exercises use common devices such as a hair dryer and a blender. Common devices are used for two reasons. Since they are already familiar to the students, the purpose and operation of the devices are already apparent, saving time and allowing the students to focus on the principles rather than the equipment. The second reason is that the equipment is inexpensive. All of the exercises use a guided inquiry pedagogy in which key questions are posed to the students who then conduct experiments to try to find the answers. This workshop introduces the participants to the full suite of exercises. After receiving some basic background on qualitative reasoning, and some “warm-up” exercises the participants will have the opportunity to conduct two abbreviated exercises. This will be followed by a general discussion of their experience with them, the pedagogy in general and suggestions for improvements or additions to the suite.

Numerical Modeling of Flow in a Large Quench Tank

A computational fluid dynamics (CFD) model is developed to simulate isothermal flow in a large quench tank used for heat treating of steel. As a surrogate for a full simulation of quenching, the isothermal model enables a computational economical comparison of many different design configurations of the quench tank. The model includes most of the geometric complexity of the tank including the skip, the heavy beams used to support it, deflector baffles used to control the flow, and the inlet ducting. Partial factorial screening studies are conducted to identify the most important design variables. The second phase of the project involves examining four new conceptual designs for the quench tank. The outcome of the second phase was the identification of a promising new design that could be realized by the addition of ducting to the existing design. The contributions of this research include a better understanding of the parameters affecting large scale batch quench processes and the development of new directions for quench tank design.Copyright