An Innovation‐Based Fluid Mechanics Design and Fabrication Laboratory

As part of a four‐week fluid mechanics laboratory, Mechanical Engineering students were challenged to design and manufacture the least restrictive flow nozzle for a standard test condition within several design constraints. The Nozzle Design Challenge (NDC) combined analysis, design, manufacturing, and experimentation. The positive student responses to the NDC were overwhelming. Formal evaluation of the NDC included the measured nozzle flow rates and the amount of time spent in the laboratory. The highest flow rate nozzle allowed substantially more flow than the nozzle with a 1‐inch diameter hole used for demonstration. Every group spent more time in the laboratory than was scheduled, which may indicate high levels of motivation for the project. The examination scores covering the principles learned in this laboratory were compared to the previous semester's students who did not perform the innovation‐based design and fabrication project. After blocking out the effects of GPA, the results indicate that the students who undertook the design experience performed significantly better on the examination.     

Enhancing the Learning of Fluid Mechanics Using Computer Simulations

This paper reports the results of a study into the impact of computer simulations on the understanding of fluid mechanics by engineering students. A “lesson study” approach was taken, using constructivist educational theory combined with the variation theory of learning from phenomenography to inform the design of learning activities and to assess their impact. Student difficulties with fluid mechanics concepts were assessed using questions from the Fluid Mechanics Concept Inventory (FMCI). Students had the greatest difficulties with pressure measurement, fluid flow through pipes with changing diameter, and velocity profiles for fluid between flat plates. We developed a set of three simulations to address these difficulties. The impact of the simulations was gauged by a second administration of the FMCI. Most of the students in the sophomore fluid mechanics class participated in the whole of this exercise. Students showed significant improvement in two of the three areas of difficulty. Student feedback on this as an additional learning exercise was very positive.     

计及减振器非线性阻尼的自行火炮车体振动试验及数值模拟

为了研究减振器的非线性阻尼特性对轮式自行火炮连发射击过程中车体振动的影响,基于流体力学和液压基本理论,通过建立减振器的非线性阻尼求解模型,得到减振器阻尼及刚度系数表达式。针对某轮式自行火炮的具体结构特点,推导由减振器引起的悬挂等效阻尼系数和等效刚度系数表达式。同时,对轮式自行火炮连发射击时车体振动进行试验测试。在理论研究和试验研究基础上,对减振器阻尼及刚度系数采用线性和非线性表达式两种状态进行了数值建模模拟。结果表明,考虑非线性阻尼及刚度系数仿真结果与试验结果吻合较好,而采用线性阻尼及刚度系数仿真结果与试验结果存在较大的误差。研究结果表明减振器非线性阻尼及刚度系数对轮式自行火炮车体振动具有较大影响。所述方法可以推广到其他火炮车体振动仿真研究中。     

Hands-on Demonstrations: An Alternative to Full Scale Lab Experiments

Short demonstrations of basic fluid mechanics principles were developed for use in 50 minute seminar sessions, led by graduate student TA's. These have provided structured training for our TA's, lightened the load on our undergraduate lab facilities, and provided our students with visual, active learning opportunities. The demonstrations and handouts were developed by an undergraduate student as a summer project, and expanded on by successive TA's. The response from the students is best illustrated by the increase in seminar attendance from 30% to over 80%.     

An Introduction to Mechanical Engineering Design for Sophomores at Purdue University

Universities play a key role in developing future engineers who understand the full scope of the product realization process, and are well equipped to produce effective, creative solutions to open-ended problems. A key step toward instilling the problem-solving mind-set in students is to lay the proper foundation early. Thus, a new cornerstone course, Introduction to Mechanical Engineering Design, has been developed in the School of Mechanical Engineering at Purdue University to bridge the gap between the freshman science and mathematics courses, and the more traditional mechanical engineering core courses such as thermodynamics, heat transfer, fluid mechanics, and machine design. This paper presents the goals of the new sophomore course, some details of its implementation, and results of the first three offerings. The primary goal of the course is to teach the students effective strategies for solving problems that have many acceptable solutions. This goal is met by a mixture of design theory presentations and design practice in a carefully guided semester-long project. Distinction is made throughout the course between effective problem-solving strategies for single-solution problems, common in math, physics, and chemistry courses for example, and multiple-solution problem-solving strategies. Results from the first three offerings of this course indicate that it is changing the way students approach problems in their later courses. Plans for future revisions of the course are also included.     

Teaching Multi‐Disciplinary Design: Solar Car Design

Multi‐disciplinary design can be taught in a very general way focusing on methods and procedures that work for any multi‐disciplinary design project or in a very specific way focusing on a specific multi‐disciplinary design project. The general approach teaches students the principles of how to approach any multi‐disciplinary design project but often lacks meaningful examples of how the principles are applied. Focusing on a specific multi‐disciplinary design project gives the students a meaningful example of how to apply design principles but they may have difficulty generalizing what they have learned and how it can be applied to other projects. To get a good background in engineering design, engineering students should have educational experiences that are both general and specific. This paper describes a course developed at the University of Missouri‐Rolla (UMR) to teach multi‐disciplinary design by focusing on the design of a solar racing car. The purpose of the course is to teach the aspects of a multi‐disciplinary design project utilizing a specific example for student comprehension.     

A Multidisciplinary Engineering Laboratory Course

The Colorado School of Mines (CSM) curriculum was recently modified by replacing laboratory courses in electrical circuits, fluid mechanics and stress analysis with a sequence of Multidisciplinary Engineering Laboratory courses (MEL I, II, and III). The MEL sequence prepares students for their professional careers by integrating discipline-specific components into systems and building subject-matter depth through a vertical sequence. The experiments move beyond basic theory verification by requiring students to practice higher level thinking. In addition, the systems experiments encourage students to reorganize knowledge and discover the connections among concepts in several courses. The MEL sequence helps students understand relationships among science, engineering science, and engineering design. The MEL experiments develop life-long learning skills by encouraging higher levels of thinking on the Perry scale and requiring students to use a variety of Kolb's learning styles. This paper describes the educational objectives and experiments for the MEL I course. The paper gives assessment results for MEL I and compares it with traditional laboratories.     

Addressing Common Problems in Engineering Design Projects: A Project Management Approach

In using projects to teach engineering design, the instructor faces the question of how to structure the process to insure an effective learning environment without compromising the independence and open‐ended nature of the student's experience. The instructor faces the problems of student time scallop (the tendency to increase effort exponentially as the final deadline approaches), of potential laggards in a group (students doing little work and getting credit for the group's results) and of students learning appropriate work documentation habits. All of these problems are project management issues and project management tools can be used to solve them. This includes both the instructor's and the student's use of project management tools. In our process, students use three key techniques to address these issues: 1. a milestone schedule, 2. regular project review meetings and memos and 3. design memos which document each design task as the project progresses. Greatest success results when students utilize all three of these tasks. Both students and instructors have experienced reduced time scallop. A memo portfolio provides a measure of individual student performance. Students turn in improved projects, learn some basic project management tools, and gain experience at regular documentation of their work.     

Biomechanics of male erectile function.

Two major branches of engineering mechanics are fluid mechanics and structural mechanics, with many practical problems involving the effect of the first on the second. An example is the design of an aircraft's wings to bend within reasonable limits without breaking under the action of lift forces exerted by the air flowing over them; another is the maintenance of the structural integrity of a dam designed to hold back a water reservoir which would exert very large forces on it. Similarly, fluid and structural mechanics are involved in the engineering analysis of erectile function: it is the hydraulic action of increased blood flow into the corpora cavernosa that creates the structural rigidity necessary to prevent collapse of the penile column.     

A Comparison of Group Processes,Performance, and Satisfaction in Face‐to‐Face Versus Computer‐Mediated Engineering Student Design Teams

Industry often requires engineers to work in teams. Therefore, many university engineering courses require students to work in groups to complete a design project. Due to the increasingly global nature of engineering, opportunities for students to navigate the issues of distance, time, culture, language, and multiple perspectives associated with virtual teams are becoming particularly desirable. To understand students' experience with virtual teams in a graduate course on principles of lean manufacturing, a group of researchers at a midwestern university compared the project performance, selected group processes, and satisfaction of students randomly assigned to face‐to‐face and computer‐mediated communication design teams. Students in both the face‐to‐face and computer‐mediated communication design teams performed equally well on the final project, and reported similar patterns in group processes with a few exceptions. Students in face‐to‐face design teams were more satisfied with the group experience than those in the computer‐mediated communication design teams; however, all reported an overall positive experience.     

Computational aircraft dynamics and loads

An alternative approach that has the potential to advance classical methods of flight load prediction by combining computational fluid dynamics (CFD), structural flexibility and the interaction of flight control system (FCS) in a multidisciplinary analysis package is described. The method employs the concept of system identification to characterize aircraft dynamics in the state space coordinate system and includes an adaptive control law design methodology. An extended account of the theoretical basis for the new multidisciplinary flight manoeuvre analysis will be presented in one of a seven-volume series on computational mechanics by Argyris and his associates to be published shortly. However, as a precursor to the complete work, a brief account of the theoretical development leading to this loads prediction methodology is included in this paper. The computational effort of this project was supported by IBM of the United States of America.     

基于车体协同的铁路运输轮式货物轮挡设计

目的 为保证运输安全,轮式货物在铁路运输过程中需要用轮挡限位。针对我国铁路运输轮式货物的现状及存在的问题,提出车体与加固装置协同设计的理念,设计一种轮挡可调式,适用于多种规格的轮式货物,存用一体、可靠性高、使用快捷。方法 利用SolidWorks建立轮挡三维模型,通过铁路运输加固强度计算,确定在最不利状况下对轮挡的强度要求,进行载荷和约束分析,利用有限元分析软件SolidWorks simulation进行仿真计算及强度分析。结果 得到该轮挡在最不利工况下的应力及位移情况。最大应力出现在轮挡底面与活动销连接部位,最大应力值为499.9 MPa,不超出设计所用材料的许用应力（585 MPa）;最大位移为0.99 mm,在允许范围内。结论 该轮挡的强度满足安全运输的要求,用于多种轮式货物铁路运输装载加固,可有效提高加固效率。     

Resin infusion-based processes simulation : coupled Stokes-Darcy flows in orthotropic preforms undergoing finite strain

The aim of this paper is to present an overall model for the study of resin infusion based processes, in particular, the impregnation of a liquid resin through dry deformable fibrous reinforcements. This model can be appliedto a wide range of activities in many fields of engineering. Here, our approach based on a monolithic formulation in a level-set framework allows to strongly couple a Stokes-Darcy flow in low permeability media undergoing finite strains. The Stokes-Darcy coupled problem is solved using a mixed velocity-pressure formulation stabilized by a multi-scale method. A key feature of our approach is the fluid-solid interaction leading to couple a fluid/porous flow to a non-linear solid mechanics formulation. The interaction phenomenon due to the resin flow in the orthotropic highly compressible preform is based on both Terzaghi’s law and on explicit relation expressing permeability as function of porosity in finite strains mechanical framework. Finally, simulations of industrial design parts are performed to illustrate the abilities of our approach and the relevance of this fluid/porous-solid mechanics coupled problem for composite material process simulations.     

Quality Improvement Partnerships with Industry Using Student Teams

The 1993 Quality Challenge is a cooperative partnership between Milliken and Company, the National Science Foundation and three North Carolina Universities. The project goal was to activate a multidisciplinary team of students, faculty, and industry representatives in a real-world quality improvement project. The 1993 project was an expanded follow-up to the 1992 University Challenge Project, also sponsored by Milliken. Based upon past experience, project coordinators broke the 1993 project into three components: Preparation, Identification, and Action. Preparation included a preliminary course held in the Spring to teach students fundamental Total Quality Management tools, team building skills and communication skills needed in industry. A team of students was selected from the course to participate in the summer Identification and Action phases of the project. The Identification phase included introduction to project goals, team process training, specialized team formation and project focus. The Action phase of the project included process capability studies, shade variation studies, root cause trials and a statistical design of experiment on shade variables. The project resulted in many recommendations to improve the process and reduce shade variation. The overall project methodology and approach can be applied to industries other than textile manufacturing. Educational benefits for all participants included: team building and teamwork experience, enhancement of effective communication skills, experience in design of experiments, engineering design and practice, greater self confidence, and industrial experience with real-world quality improvement opportunities.     

Student Participation,Faculty Involvement,and Costs in the NGV Challenge — A Large-Scale Automotive Design Project

Large-scale automotive design projects offer an outstanding opportunity for students to obtain practical experience in engineering design. This paper reports a survey of faculty advisors for student teams participating in the Natural Gas Vehicle Challenge. About fifteen students were typically involved in the project at each university participating in the competition. Five or six were typically “key” to the project. Usually faculty advisors had a research interest in automotive engineering or alternate fuels, and they often incorporated the project into a design course. Although the funding level for such a design project varied substantially, the typical funding level was about $25,000, most of which came from local sponsors. Faculty advisors often commented on the educational value of the project and their satisfaction in working closely with students.     

Hands‐On CFD Educational Interface for Engineering Courses and Laboratories

This study describes the development, implementation, and evaluation of an effective curriculum for students to learn computational fluid dynamics (CFD) in introductory and intermediate undergraduate and introductory graduate level courses/laboratories. The curriculum is designed for use at different universities with different courses/laboratories, learning objectives, applications, conditions, and exercise notes. The common objective is to teach students from novice to expert users who are well prepared for engineering practice. The study describes a CFD Educational Interface for hands‐on student experience, which mirrors actual engineering practice. The Educational Interface teaches CFD methodology and procedures through a step‐by‐step interactive implementation automating the CFD process. A hierarchical system of predefined active options facilitates use at introductory and intermediate levels, encouraging self‐learning, and eases transition to using industrial CFD codes. An independent evaluation documents successful learning outcomes and confirms the effectiveness of the interface for students in introductory and intermediate fluid mechanics courses.     

Multi‐University Design Projects

We describe a multi‐university design project in which teams of students across different campuses collaborate on a design and manufacturing project. We show how such projects sensitize students to issues in concurrent engineering and train them in interpersonal skills, communications, and system integration. We believe that this approach allows us to simulate real‐world conditions by imposing realistic boundary conditions on the student teams.     

Interdisciplinary Laboratory in Advanced Materials: A Team‐Oriented Inquiry‐Based Approach

Few opportunities exist in most undergraduate engineering curricula for students of different disciplines, even within engineering, to work together. This project demonstrates a way to interject such activities by bringing together students across disciplines from otherwise independent courses. In this first phase of activities at Tennessee Technological University (TTU), chemical engineering (ChE) students from a required laboratory course and mechanical engineering (ME) students from a design elective were brought together in a common interdisciplinary‐team inquiry‐based term project. This report summarizes the course objectives and structure, offers a brief synopsis of the outcomes and direction for the project.     

A Freshman Engineering Design Course

At the University of Maryland at College Park, a new freshman engineering design course introduces design through a project approach. This approach has three phases: design, manufacturing and assembly. First, students learn basic engineering concepts by designing a simple product. Next, they manufacture and/or procure the product's components. Finally, they assemble the components and test the finished product. Since drawings for this product are part of the project, students must also learn entry-level computer graphics. Reaction to teaching design so early in the engineering curriculum has been extremely favorable. Students are highly motivated by the design approach and, as a result, learn engineering fundamentals, develop critical thinking skills, learn to cooperate as team members and gain practical hands-on experience.     

A Learning Community of University Freshman Design,Freshman Graphics,and High School Technology Students: Description,Projects, and Assessment

A learning community was developed to enhance the teamwork and communication components of a freshman design course. The learning community was comprised of students from a freshman design course, a freshman graphics course, and a high school technology course. Design teams were formed by combining three to four students from each of these courses. These teams were required to research, design, build, and test a specified product. The high school and university students communicated only using e‐mails and Internet conferencing. This paper outlines how the learning community is implemented, describes three design projects, and presents the assessment methods. Assessment reveals that university students who participate in the learning community have a better understanding and confidence in the technical aspects of the design project than the students who do not participate in the learning community. It also reveals that high school participants display notable interest in the engineering design process.