Current Search:   Hoekstra, Robert (x)

View All Items

  • CSV Spreadsheet
(1 - 5 of 5)
NASCAR RESTRICTOR PLATE EXHAUST MANIFOLD DESIGN STRATEGIES
Title
NASCAR RESTRICTOR PLATE EXHAUST MANIFOLD DESIGN STRATEGIES.
Creator
Dollhopf, Matthew John, Hoekstra, Robert, University of Central Florida
Abstract / Description
This paper presents the results of a study on exhaust manifold design for a NASCAR Restrictor plate internal combustion engine. A computer simulation model was developed using Ricardo WAVE software. WAVE is a computer-aided engineering code developed by Ricardo to analyze the dynamics of pressure waves, mass flows and energy losses in ducts, plenums and the intake and exhaust manifolds of various systems and machines. The model was validated against experimental data from a current NASCAR...
Show moreThis paper presents the results of a study on exhaust manifold design for a NASCAR Restrictor plate internal combustion engine. A computer simulation model was developed using Ricardo WAVE software. WAVE is a computer-aided engineering code developed by Ricardo to analyze the dynamics of pressure waves, mass flows and energy losses in ducts, plenums and the intake and exhaust manifolds of various systems and machines. The model was validated against experimental data from a current NASCAR Winston Cup restrictor plate motor. The parameters studied have been exhaust manifold diameters and lengths. A response surface analysis of the simulation output followed.The analysis of results shows the design parameters of the existing exhaust manifold are not optimized. The findings from these studies are used to derive exhaust system design guidelines which define optimum exhaust system geometry to maximize average Brake Horsepower over a given powerband for a restrictor plate NASCAR engine.
Show less
Date Issued
2004
Identifier
CFE0000082, ucf:46087
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000082
INVESTIGATION OF NASCAR RESTRICTOR PLATE MANIFOLD INSERT USING WAVE ENGINE SIMULATION AND RESPONSE SURFACE METHODOLOGY
Title
INVESTIGATION OF NASCAR RESTRICTOR PLATE MANIFOLD INSERT USING WAVE ENGINE SIMULATION AND RESPONSE SURFACE METHODOLOGY.
Creator
Gross, John Mason, Hoekstra, Robert, University of Central Florida
Abstract / Description
With the increasing growth in computer processing power, computer based computational fluid dynamics simulations are finding increasing acceptance and use in the field of internal combustion engine development. Once fully developed, such simulations provide detailed and expedient tools for testing existing theories, as well as new ideas. While numerous studies on wave propagation and fluid flow in intakes manifolds exist, most restrict the analysis to a single intake runner and port,...
Show moreWith the increasing growth in computer processing power, computer based computational fluid dynamics simulations are finding increasing acceptance and use in the field of internal combustion engine development. Once fully developed, such simulations provide detailed and expedient tools for testing existing theories, as well as new ideas. While numerous studies on wave propagation and fluid flow in intakes manifolds exist, most restrict the analysis to a single intake runner and port, examining only the dynamics from the runner-to-plenum junction downstream to the valve. While such analyses provide comprehensive models for wave propagation dynamics in the runner, little is published on the fluid dynamics and wave propagation in the plenum, and the interactions between runners when an intake manifold's geometric constraints prevent symmetry in the manifold. This paper will examine the modeling of a 2003 specification Dodge Motorsports NASCAR Restrictor Plate engine using Ricardo's WAVE engine simulation computational fluid dynamics software. This examination will include an introduction to the software and required engine data for constructing a comprehensive model, the process used to validate the simulation's output with acquired engine performance data, and the use of response surface methodology to optimize the dimensions of the plenum insert associated junction. Additionally, an analysis of the problems with modeling this area of the manifold using one-dimensional CFD will be conducted, as well as a discussion of the theories surrounding the insert. Finally, a new hypothesis regarding the insert as well as future work to examine this hypothesis will be introduced.
Show less
Date Issued
2004
Identifier
CFE0000124, ucf:46204
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000124
Modeling the innovation ecosystem and development of a dynamic innovation index
Title
Modeling the innovation ecosystem and development of a dynamic innovation index.
Creator
Schoen, Henriette, Karwowski, Waldemar, Hoekstra, Robert, Shumaker, Randall, Akbas, Mustafa, University of Central Florida
Abstract / Description
The topic of innovation currently generates a tremendous amount of interest around the world. Innovation is considered an essential part of the solution to creating more jobs and improving the socio-economic conditions of many countries around the globe. Innovation comes about through the existence of many interrelated solutions to socio-economic problems in an extensively interconnected network, which create value for each other. Such a complex creativity and innovation value-creating...
Show moreThe topic of innovation currently generates a tremendous amount of interest around the world. Innovation is considered an essential part of the solution to creating more jobs and improving the socio-economic conditions of many countries around the globe. Innovation comes about through the existence of many interrelated solutions to socio-economic problems in an extensively interconnected network, which create value for each other. Such a complex creativity and innovation value-creating network is here called an Innovation Ecosystem (IE). The main objective of this dissertation research is to improve the current understanding of the IE by developing a simulation model that uses a broad set of relevant static and dynamic variables and incorporates the principles of system dynamics (SD). The proposed model, which is named the IECO-model is based on the relationships between 91 variables and the combined influences of the 43 parameters. Available data for 32 countries, representing a full span of GDP worldwide, was used to study the level of innovation in each of these countries. The result of the developed IECO-model is a novel ranking of the level of innovation through a dynamic innovation index, called the DII. The DII is a new tool to evaluate the innovation and entrepreneurship level of a given country in the context of the global economy. The most significant differentiator from other existing indices of innovation is that the DII is focusing more on the entrepreneurship qualities in 19 of the 43 parameters by looking at cultural values and belief systems, the social context, existing entrepreneurial culture, innovation attitudes, and mentality of each of the considered countries. According to DII-based ranking, the ten most innovative countries in the world are 1. Switzerland, 2. USA, 3. Finland, 4. Netherlands, 5. Iceland, 6. Sweden, 7. Germany, 8. Denmark, 9. The United Kingdom, and 10. Austria.
Show less
Date Issued
2018
Identifier
CFE0007586, ucf:52537
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007586
Successful Organizational Change: Aligning Change Type with Methods
Title
Successful Organizational Change: Aligning Change Type with Methods.
Creator
Al-Haddad, Serina, Kotnour, Timothy, Mollaghasemi, Mansooreh, Hoekstra, Robert, Diaz, Rey, University of Central Florida
Abstract / Description
The motivation behind this research is the prevalence of challenges and ambiguity associated with successful organizational change and the numerous available approaches in dealing with these challenges and ambiguity.Many definitions and methods have been suggested to manage change; however, organizations still report a high failure rate of their change initiatives. These high failure rates highlight the continuing need for research and investigation, and imply a lack of a valid framework for...
Show moreThe motivation behind this research is the prevalence of challenges and ambiguity associated with successful organizational change and the numerous available approaches in dealing with these challenges and ambiguity.Many definitions and methods have been suggested to manage change; however, organizations still report a high failure rate of their change initiatives. These high failure rates highlight the continuing need for research and investigation, and imply a lack of a valid framework for managing successful organizational change. This dissertation critically reviews the concept of having one change approach as the (")silver-bullet("). In pursuit of this goal, this research contributes a roadmap to the change management literature and provides definitions for describing change types, change methods and change outcomes. This dissertation also develops a conceptual model that proposes relationships and connections between the change types, change method and change outcomes that is assumed to enable successful change. To validate the research conceptual model, two hypotheses were developed and a self-administered survey was created and administered (paper survey and online). The respondents were professionals involved in change projects in the Central Florida region. The unit of analysis in this research was a completed change project. Respondents were asked to complete the survey for two different projects: a successful project and an unsuccessful project. Statistical processes were applied to verify the conceptual model and test the research hypotheses.Based on the data collected, exploratory factor analysis was used to verify the validity and reliability of the conceptual model measures. Results of the hypotheses testing revealed that there are relationships between the complexity of the change type and the use of change methods that significantly relate to successful change. The results also revealed that the alignment of the change type and change methods significantly relates to successful change.From the viewpoint of change project managers, the results of this dissertation have confirmed that the complexity of the change project type negatively correlates with change success and the increased use of change methods positively correlates with change success. The results also confirmed that the methods that highly correlate to change success address the following: (a) the situation that needs changing, (b) the proper implementation of change, (c) the establishment of suitable plans and controls to sustain change, and (d) the presence of a credible team leader who influences the major decisions during the change project.
Show less
Date Issued
2014
Identifier
CFE0005121, ucf:50691
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005121
An Experimental Investigation of the State of Creativity, Critical Thinking and Creativity Training in Undergraduate Engineering Students
Title
An Experimental Investigation of the State of Creativity, Critical Thinking and Creativity Training in Undergraduate Engineering Students.
Creator
Sola, Eric, Hoekstra, Robert, Kotnour, Timothy, McCauley, Pamela, Fiore, Stephen, University of Central Florida
Abstract / Description
This research explores creativity and critical thinking skills in undergraduate engineering students. The study undertook two experiments in order to gather a better understanding of several factors regarding the interactions between students' creative abilities and the effects of the undergraduate engineering curriculum. Experiment 1 focused on the differences in creative and critical thinking skills in freshman versus senior undergraduate engineering students. Experiment 2 centered on the...
Show moreThis research explores creativity and critical thinking skills in undergraduate engineering students. The study undertook two experiments in order to gather a better understanding of several factors regarding the interactions between students' creative abilities and the effects of the undergraduate engineering curriculum. Experiment 1 focused on the differences in creative and critical thinking skills in freshman versus senior undergraduate engineering students. Experiment 2 centered on the variation in the effects of long-term versus short-term creativity training on senior engineering students. Creative skill was measured using the Test for Creative Thinking (-) Drawing Production (TCT-DP) developed by Urban and Jellen (2010). Measurements for critical thinking utilized the Watson-Glaser Critical Thinking Assessment (WGCTA) (Watson (&) Glaser, 2008).Experiment 1 found evidence suggesting the freshman engineers within the study were more creative than senior engineers (F = 3.159, P-Value = 0.078). Surprisingly, there was no evidence suggesting the senior engineers had superior critical thinking skills over the freshman engineers (F = 1.054, P-Value = 0.306). The study groups' data was also compared to the normative data provided by the WGCTA test, in order to determine the standing of the two engineering sample groups against the general population. The study's freshman group average ranked in the 70th percentile (freshman engineers' average) when compared to the normative general population's average (50th percentile). The senior participants, on the other hand, scored significantly lower than their corresponding normative group, moving from the 50th percentile (normative average) to slightly above the 35th percentile (senior engineers' average). Based on this evidence, current engineering education methods are detrimental not only to the creative skills of engineering students, but their critical thinking capabilities as well.Experiment 2 results suggested that long-term creativity training provides statistically significant improvements over short-term creativity training (F = 40.381, P-Value = 0.000). This significance was established even though the long-term group was found to have been trained inadvertently before the start of their official training, simply by their knowledge of the course's requirements to provide creative solutions. As such, these results suggest both that continuous creativity training benefits the recipient individuals, and that beginning a more creative approach to collegiate engineering curricula may start as easily as initiating courses with the known expectation that students use creativity in their problem solving whenever feasible. This study provides new insights into the state of creativity and critical thinking in undergraduate engineers. Based on the resulting data, engineering education must be examined and restructured to provide students with the necessary tools to improve their creative and critical thinking skills. Through the use of creativity and critical thinking training and instruction methods, educators can effectively address these observed deficiencies, resulting in engineering students being better prepared for their professional lives within the 21st century workplace.
Show less
Date Issued
2016
Identifier
CFE0006183, ucf:51134
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006183