Fluid-Wall Interactions in Pseudopotential Lattice Boltzmann Models

Designing proper fluid-wall interaction forces to achieve proper wetting conditions is an important area of interest in pseudopotential lattice Boltzmann models. In this paper, we propose a modified fluid-wall interaction force that applies for pseudopotential models of both single-component fluids and partially miscible multicomponent fluids, such as hydrocarbon mixtures. A reliable correlation that predicts the resulting liquid contact angle on a flat solid surface is also proposed. This correlation works well over a wide variety of pseudopotential lattice Boltzmann models and thermodynamic conditions

Lessons from Two Years of ePortfolio Implementation in Engineering Technology Courses

In an undergraduate as well as in a graduate academic setting, an ePortfolio is a collection of student work designed to exhibit student’s achievements, which often includes student’s reflective commentaries. While in academia ePortfolios are used to document the student learning process over time, they have been also well received by employers as work portfolios or showcases. This paper provides detailed explanations of two years of implementation of ePortfolio activities in junior and senior level engineering technology courses. The goal of the paper is to present to the community the best practices learned during the implementation and to provide information on how the ePortfolios can be integrated with other course assignments, enhancing the course outcomes but without raising the burden from the instructor perspective. Class material samples are provided in the Appendix. The best received implementation was observed when: 1) scaffolding of the activity was done along the semester and was aligned with the pre-existing course activities (such as test, HW assignments, etc.), 2) the eP project was made optional for extra credit, 3) detailed instructions were provided, and 4) a website template was provided

Fugacity-Based Lattice Boltzmann Method for Multicomponent Multiphase Systems

The free-energy model can extend the lattice Boltzmann method to multiphase systems. However, there is a lack of models capable of simulating multicomponent multiphase fluids with partial miscibility. In addition, existing models cannot be generalized to honor thermodynamic information provided by any multicomponent equation of state of choice. In this paper, we introduce a free-energy lattice Boltzmann model where the forcing term is determined by the fugacity of the species, the thermodynamic property that connects species partial pressure to chemical potential calculations. By doing so, we are able to carry out multicomponent multiphase simulations of partially miscible fluids and generalize the methodology for use with any multicomponent equation of state of interest. We test this fugacity-based lattice Boltzmann method for the cases of vapor-liquid equilibrium for two- and three-component mixtures in various temperature and pressure conditions. We demonstrate that the model is able to reliably reproduce phase densities and compositions as predicted by multicomponent thermodynamics and can reproduce different characteristic pressure-composition and temperature-composition envelopes with a high degree of accuracy. We also demonstrate that the model can offer accurate predictions under dynamic conditions

Attainment of Rigorous Thermodynamic Consistency and Surface Tension in Single-Component Pseudopotential Lattice Boltzmann Models via a Customized Equation of State

The lack of thermodynamic consistency is a well-recognized problem in the single-component pseudopotential lattice Boltzmann models which prevents them from replicating accurate liquid and vapor phase densities; i.e., current models remain unable to exactly match coexisting density values predicted by the associated thermodynamic model. Most of the previous efforts had attempted to solve this problem by introducing tuning parameters, whose determination required empirical trial and error until acceptable thermodynamic consistency was achieved. In this study, we show that the problem can be alternatively solved by properly designing customized equations of state (EOSs) that replace any cubic EOS of choice during the computation of effective mass used in Shan-Chen forces. A two-parameter cubic-shaped customized EOS is introduced. Contrary to previous efforts, customization parameters in the new EOS are nonempirical and are rather derived from solving the integral mechanical stability equation, which neglects the need for any type of tuning for the attainment of rigorous thermodynamic consistency. The proposed approach reduces the errors of the coexisting densities and saturated pressure in the simulation to a maximum of 0.01% within the liquid-vapor density ratio range from O1 to O(104), which had not been achieved in any of the previous tuning-based efforts. A straightforward way for achieving the desired surface tension via the customized EOS is also provided

Flipped Classroom as Blended Learning in a Fluid Mechanics Course in Engineering Technology

Flipped classroom has gained attention in recent years as a teaching method in which the time allocated for introducing new concepts and the time used for practicing them are inverted, in order to provide more time for problem based learning and class interaction under direct supervision of the instructor. The implementation of this teaching method is comprised of two main components, the pre-class activities, which consist of individual student work and are largely based on pre-recorded videos, and in-class activities, which are group activities supervised by the instructor. This paper discusses the implementation of the flipped classroom method in a Fluid Mechanics course in an Engineering Technology program at a midsize university. The study presented was conducted over four consecutive semesters, the data representing four different groups of students. In the study presented, an important percentage of the students took the course in an online setting, either synchronous or asynchronous mode, which created an atypical situation compared to other implementations of flipped classroom method presented in the literature. It was found that the length or the format of the pre-recorded videos were not critical factors in determining the students to review them before the class. The unconventional setting of the class, including both in class and online students, required originality in handling the in-class activities. The best approach was to delegate students to lead the group discussions associated with solving the problems, while the instructor acted as an observer when the discussions were constructive and as a guide when the solution was getting out of rail or when the students were struggling. A survey was distributed to the students at the end of the course as a post-class activity, concluding the implementation considered in the study. The results of the survey showed that the students were satisfied with the teaching method and found it important in their learning process

Manual Revision Process for Project-Based Laboratory Instruction

A four-step laboratory manual revision process was developed in this study based upon a technical writing process for supporting project-based laboratory classes. The audience and the objectives of this type of laboratory manuals are quite different from those of traditional, descriptive laboratory classes. The project-based laboratory manual has to serve as both an operational handbook and a theoretical textbook. The proposed four-step manual revision process was implemented in the fall 2016 semester in a 3-credit, senior elective class which was built upon a commercially-rated finite element analysis software package. Student surveys and evaluations showed that the revision process greatly increased student engagement in the class and, as a result, increased student learning effectiveness

Implementing Peer-Review Activities for Engineering Writing Assignments

Professional engineers spend a considerable portion of their day writing, yet disciplinary writing skills are not addressed in many engineering courses. This study investigates peer review as a mean to enhance student writing in engineering courses. Students completed formative peer reviews using an online peer review system for a group project in a fluid mechanics course (with online and face-to-face sections) and for an individual writing assignment in a senior capstone class in mechanical engineering. A university-wide rubric for disciplinary writing was used to assess student writing performance on interim and final assignments completed over the course of a semester. Online surveys were used to assess student perceptions of the peer review process. The study was implemented over two semesters with iterative revisions in instruction made between semesters based on initial findings. Results suggest that peer review can increase student performance, as long as reflections are used to prompt student revision, regardless of the class delivery method or assignment type

The Use of Polleverywhere in Engineering Technology Classes to Student Stimulate Critical Thinking and Motivation

Critical thinking is considered one of the most important aspects of the learning process at the college level, especially in the field of engineering technology. However, developing critical thinking can prove to be quite challenging. It takes a lot of instructional effort and support for undergraduate students enrolled in engineering technology programs to develop the ability to analyze, adequately synthesize conceptual knowledge, and then apply that knowledge to practical problem-solving situations. This ability is a critical component of any successful completion of job responsibilities for future engineers. In this study we examine the effectiveness of the web-based polling system Polleverywhere in promoting all stages of learning, with the emphasis on acquisition and generalization of new knowledge. The study also evaluates the effectiveness of the above-mentioned web-based system in promoting students\u27 motivation. Besides traditional face-to-face interaction in class (students asking questions and verbally responding to the instructor\u27s questions) students were engaged in class participation through the use of Polleverywhere software. A polling system increases the likelihood that all students in the class answer the questions presented. Furthermore, after polling, students can compare and discuss their answers across the entire group. This is a peer-review process important in the success of their learning. A survey was administrated towards the end of the class and data from this survey was used in the analysis. The evaluation in this study is based on a Circuits course in electrical engineering technology, for a relatively small-lecture classroom

Integrating Statistical Methods in Engineering Technology Courses

Statistical methods and procedures are very important in engineering applications. In most of the engineering fields electronic devices are used as sensing and controlling components. Lack of proper calibration of these devices and of performance analysis using different statistical methods may lead to erroneous measurements and results. In medical or manufacturing areas such errors in the experimental results could be catastrophic. Applying different statistical tests and procedures enhance the quality of engineering work. Traditionally, most engineering curricula have at least one required course in applied statistics in engineering, but that is not generally the case in engineering technology programs. Most of the engineering technology BS graduates work as field engineers and collect the data from different physical processes and do data analysis to validate the systems performances. Exposure to statistical methods use and data analysis will provide technology graduates with valuable skills in the current high-tech job market. This paper focuses on how statistical analysis and methods using hand calculations and software tools can be integrated in undergraduate engineering technology courses, enhancing the hands-on approach of real engineering projects with software assisted data analysis. Learning the skills of collecting experimental data from real processes and performing statistical analysis on it is the effective approach of solving engineering problems, and it provides higher learning outputs than simulation-based approach. Specifically, integration of statistical analysis was introduced in an industrial instrumentation class, in which the lab component included the use of various sensors and other measurement instruments. By the end of the class, students demonstrated newly acquired statistical skills by performing sensor calibration and they also applied simple linear regression analysis model on the experimental dat

Embedding Online Based Learning Strategies Into the Engineering Technology Curriculum

Various blended learning strategies have been implemented at engineering technology programs to facilitate different learning styles and different time constraints given to faculty. Some of these efforts are related to the effective use of online tools such as online course management systems, ePortfolios, narrated presentations, web-based polling systems, tutorials and educational materials posted before the class and asynchronous learning methods. As technology changes, some of the online learning methods are getting more advanced which is enabling more innovative approaches and data compression. Various distance learning programs started with having access to videos of recorded lectures (on VHS tapes, or CDs) and further they went to use of new media which followed the use of online based strategies such as online management systems, use of social media, podcasts, and other means of communication to deliver the instruction. It became easier to share videos to a wider audiences and enable easier access to state of the art in development in new engineering areas. Accessing pre-recorded educational modules is now easier with new wireless gadgets, with widespread networking capabilities on campuses and outside the campus. In this way, students have opportunities to spend more time in interacting with faculty in class, not only in their assigned office hours. These teaching and learning methods are emphasizing a not so new educational principle, the Socratic method. This concept is especially important for universities with diverse student population which include working adult student population, students who are with the military, students who have families and all other which are non-traditional students who do not live on campus. In this paper, embedding online based learning strategies into the classroom efforts in Engineering Technology department at one midsize institution is discussed