Browsing by Author "Wise, Dan, committee member"

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Embargo
Determining systems engineering value in competitive bids
(Colorado State University. Libraries, 2023) Dawson, Sandra Lynn, author; Batchelor, Ann, advisor; Arenson, David, committee member; Adams, James, committee member; Simske, Steve, committee member; Wise, Dan, committee member
Corporations need a methodology to determine existing and new Systems Engineering (SE) effort costs in a more relevant context through deepening its connection within the competitive bidding process. The impact of Digital Engineering (DE) on SE within competitive bids is evolving as the industry is maturing its DE transition and implementation. The state of the field does not consider the impact of the current transition from traditional document-based SE (TDSE) to digital engineering (DE) and the impact on SE value. This paper examines the effectiveness of the SE costing models that are available in the literature by introducing a process to compare completed projects using metrics of actual SE hours expended and project performance against recommended SE effort and project results. Analysis of this comparison provides justification for SE effort bid ranges and associated project results. This research endeavors to enable a more holistic and SE-centric view of SE costing with considerations of project characteristics and the ongoing DE transition. Finally, this research provides a new framework for the analysis results and references useful in the bidding of SE projects where SE bid options can be associated with project performance, DE transition progress, and references relevant to the competitive bid approach. By applying systems thinking, using feedback loops and data from multiple organizations, understanding SE-DE impact, and empowering engineers in the DE transition, these research results enable data-driven decisions to determine SE value in competitive bids and to optimize SE using risk management. Following this process and using an organization's data (for competitive bids and projects) will yield results specific to competitive bids, bid technical approach, and DE transition progress. These results are communicated to the competitive bids teams using a SE focused framework.
Open Access
Development of advanced combustion strategies for heavy duty LPG engines to achieve near-diesel efficiency
(Colorado State University. Libraries, 2024) Fosudo, Toluwalase Jude, author; Olsen, Daniel B., advisor; Windom, Bret, committee member; Wise, Dan, committee member; Grigg, Neil, committee member
As the transportation sector evolves in response to increasingly stringent emissions regulations and economic realities in the wake of the decarbonization drive, several no/low carbon fuel options have emerged as viable options for internal combustion engines. Among these fuels, Liquefied Petroleum Gas (LPG) is uniquely positioned for spark ignited engine operation due to its favorable physical and chemical properties. Currently, much of its use as an engine fuel is limited to light-duty applications, dual fuel applications, or retrofitted gasoline engines, with a lesser degree of penetration into the heavy-duty sector where diesel fuel still dominates. A key reason for this is the deficit in performance and efficiency between diesel and other low carbon fuels, including LPG, necessitating the need for targeted research aimed at bridging this gap, and positioning LPG as a fuel of choice in the heavy-duty sector. Two prominent drawbacks responsible for this gap between diesel and LPG engine performance are the dearth of specialized fuel injection hardware and tailored injection strategies, and knock, which limits the performance of spark ignited engines. This work seeks to address these and other limitations and achieve near diesel efficiency on a heavy-duty engine platform. Two engine platforms were employed in this study. A cooperative fuel research (CFR) spark-ignited engine was used to study the knock dynamics and the performance, combustion, and emissions behavior of the LPG fuel in relation to key engine parameters, the LPG fuel composition, and other low carbon fuel options. Compression ratio, engine load, exhaust gas recirculation percents, and a novel combustion control tool, the combustion intensity metric (CIM), were all varied on the CFR engine and a computational fluid dynamics (CFD) model calibrated and validated. Key findings were then transferred to a heavy-duty engine platform, the Cummins ISX15L single cylinder engine. The engine is a converted 6-cylinder diesel engine with diesel brake thermal efficiency (BTE) of 44%. A baseline evaluation was conducted with liquid LPG port-injected at 16bar and 9.3:1 compression ratio. Then the engine was switched to direct injection (DI) configuration with a fuel delivery system capable of delivering liquid LPG at pressures up to 200bar. Three principal configurations were developed for operation of the heavy-duty engine employing a gasoline direct injector (GDI) with nozzle patterns adapted for optimal distribution of the LPG fuel in the combustion chamber, a GDI modified for higher LPG flow and a double-injector port-fuel injection (PFI) system optimized for injection location, and charge cooling and distribution. The experiments and modeling contained in this study demonstrate the impact of LPG composition on engine performance, the mitigating effect of EGR on knock and NOx emissions, the potential for a better controlled combustion using the CIM tool and the advantages in terms of knock, performance, and emissions of designing an injection strategy tailored to the LPG fuel. The results show that the heavy-duty engine operated on LPG achieved the target efficiency of 44% BTE at high EGR, high compression ratio, and high load conditions for both DI and PFI configurations. The outcomes of this study advance the literature on knock, end-gas autoignition, emissions, and EGR related to LPG and its use as a choice fuel for heavy-duty applications and advances the development of specialized fuel delivery hardware and injection strategies for the LPG fuel.
Open Access
Development, testing, and validation of a heat transfer model for bi-propellant liquid rocket engines
(Colorado State University. Libraries, 2024) Roberts, Jadon A., author; Windom, Bret, advisor; Wise, Dan, committee member; Adams, Jim, committee member
Accurately modeling the heat transfer characteristics in a bi-propellant liquid rocket engine is a time and resource intensive process. The highly unpredictable and turbulent nature of the combustion requires complex modeling to predict the temperatures and fluid properties. These properties are required to evaluate material requirements and thermal performance. The primary objective of this project was to determine the effectiveness of an adaptable analytical heat transfer model implemented in MATLAB. The analytical model was pursued for the dramatic speed increase over numerical techniques such as computational fluid dynamics (CFD). The effectiveness of the model is determined by comparing results to CFD simulations as well as data obtained from testing. Strong correlations can be drawn with variations a low at 1\% between the CFD and analytical models. Three separate engines were analyzed to gauge the effectiveness of the analytical model across various engine and cooling configurations. A 10 N, 250 N and 2.9 kN thrust engines were developed. Extensive analysis was done on all engines using both the analytical model and CFD. These engines were designed with a wide range of cooling methods including radiative, ablative and regenerative cooling. A test stand previously only capable of testing hybrid rocket engines, was modified to allow for the testing of liquid bi-propellant rocket engines. The needed modifications included the addition of a fuel tank with mass measurement, venting and control valves, and fuel line sensing equipment. Upgrades were completed on the data acquisition system to incorporate additional sensors and controls. Further work was done to improve the safety of the test stand through redundancy and automation. These modifications culminated in two successful static fires of the 2.9 kN engine. The predicted temperatures of the 2.9 kN engine were compared to the test results from the static fires.
Open Access
Merging systems engineering methodologies with the Agile Scrum framework for Department of Defense software projects
(Colorado State University. Libraries, 2024) Rosson, Dallas, author; Bradley, Thomas, advisor; Batchelor, Ann, advisor; Coleman, David, committee member; Eftekhari Shahroudi, Kamran, committee member; Wise, Dan, committee member
Only large-scale Department of Defense (DoD) software projects executed under the direction of the DoD Instruction 5000.2, Operation of the Adaptive Acquisition Framework, are required to follow rigorous systems engineering methods. Many software projects lack the benefits of established systems engineering methodologies and good engineering rigor and fail to meet customer needs and expectations. Software developers trained in the use of the various Agile frameworks are frequently strongly opposed to any development methodology that could be viewed as infringing on the principles of the Agile Manifesto. Agile projects, by their nature, embrace the concept of change, but uncontrolled change leads to project failures whereas controlled change can lead to sustained and innovative forward progress. In order to improve the results of these vital software projects, Department of Defense (DoD) software projects require a methodology to implement systems engineering rigor while still employing Agile software practices. The Agile Scrum framework alone is not rigorous enough to fully document customer needs as User Stories are written tracking only who, what, and why at a non-atomic level and commonly never looked at again after development needs are met. Systems engineering methods alone are not flexible enough to take advantage of the inherent nature to change capability required in software projects, which require flexibility in schedule and requirements. A new methodology, the Systems Engineering Focused Agile Development method, takes a rigor-flexibility-rigor approach to development and makes use of the strengths of the Agile Scrum framework with the best practices of systems engineering methodologies resulting in a common language that better allows cross-functional teams to communicate project needs while also allowing software developers to maintain flexibility in the execution of software projects. This research has determined that the thoughtful blending of Agile systems engineering and modern systems engineering methods has the potential to provide DoD software projects with benefits to cost, schedule, and performance.