# Integrating Electrical Analogy and Computer Modeling of Groundwater Flow for Teaching Flownet Concepts

## Authors

• Murthy Kasi Moore Engineering, Inc.
• Yaping Chi Moore Engineering, Inc.
• G. Padmanabhan North Dakota State University

## Keywords:

Electrical analogy, flownet, groundwater, laboratory module, Visual MODFLOW.

## Abstract

Laplace equation is the basic differential equation that governs the steady flow of a fluid through an isotropic and homogeneous porous medium and also the steady flow of current in a conducting medium. Therefore, a steady-state groundwater flow problem can be formulated as an analogous electrical current flow problem. A flow net, set of grids formed by orthogonally intersecting equipotential lines and flow lines, is a graphical solution to the equations of steady groundwater flow. By definition, flownet for the original groundwater problem and the corresponding analogous electrical problem should be similar. This feature allows the possibility of introducing the concepts of flownets to students using the easily demonstrable electrical counterpart of the problem in a laboratory setting. This paper discusses the efforts of the authors to widen the scope of an experiment already included in the Fluid Mechanics laboratory course of a Civil Engineering curriculum and to better teach flownet principles using the electrical analogy of groundwater flow problems. Students used a simple experimental setup to obtain flownets for selected groundwater flow situations with different boundary conditions using the electrical analogy concept. Students also used a groundwater flow computer model to obtain flownets for the same flow situations and compared the results. The laboratory lesson plan consisted of five steps: (i) study and understand the selected physical groundwater problems, (ii) conceptualize the corresponding analogous electrical problems (iii) use the electrical analogy experimental setup to obtain flownets, (iv) study and understand the mathematical formulation of the problems, and (v) compare the analogous results with those obtained from a groundwater flow computer model. Sample results obtained by students are presented. The student feedback indicated that this approach resulted in an effective learning of the concepts involved.

## Author Biographies

### Murthy Kasi, Moore Engineering, Inc.

M. Kasi, Ph.D. is a Project Engineer at Moore Engineering, Inc., West Fargo, ND 58078 USA. He is actively involved in teaching at North Dakota State University (NDSU), Fargo, North Dakota. He taught laboratory classes for Fluid Mechanics and Environmental Engineering, and gave numerous lectures on modeling surface water quality, stormwater, and groundwater. He was a Teaching Assistant for the Fluid Mechanics Laboratory Class at NDSU in Spring and Fall of 2010 when this Flownet course module was introduced.

### Yaping Chi, Moore Engineering, Inc.

Y. Chi is a Graduate Engineer at Moore Engineering, Inc., West Fargo, ND 58078 USA. She was a Teaching Assistant in the Fluid Mechanics laboratory for undergraduates at North Dakota State University (NDSU), Fargo, North Dakota in Spring and Fall of 2011. She obtained her Bachelorâ??s degree in Management and Planning of Resources and Urban Area from Anhui University of Science and Technology, China, Masterâ??s in Hydrology and Water Resources from China University of Geosciences, China, and a Masterâ??s in Civil Engineering from NDSU.

### G. Padmanabhan, North Dakota State University

G. Padmanabhan , Ph. D., P.E., M. ASEE, F. ASCE is a Professor of Civil Engineering at North Dakota State University, Fargo, ND 58105 USA. He is a long standing member of ASEE and ASCE. He has taught Fluid Mechanics and associated laboratory course for several years in the past. He continues to teach Applied Hydrology, Open Channel Flow, and Groundwater courses. He is the Director of North Dakota Water Resources Research Institute. He has been active in Science, Technology, Engineering and Mathematics (STEM) education outreach activities to minorities at the college and high and middle school level for the last fifteen years.

2013-10-11

## How to Cite

Kasi, M., Chi, Y., & Padmanabhan, G. (2013). Integrating Electrical Analogy and Computer Modeling of Groundwater Flow for Teaching Flownet Concepts. International Journal of Engineering Pedagogy (iJEP), 3(4), pp. 39–46. https://doi.org/10.3991/ijep.v3i4.3052

Papers