Matching Items (20)
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- All Subjects: Aerospace
- Creators: Mechanical and Aerospace Engineering Program
Description
This work describes the numerical process developed for use of rocket engine nozzle ejectors. Ejector nozzles, while applied to jet engines extensively, have not been applied to rockets, and have great potential to improve the performance of endoatmospheric rocket propulsion systems. Utilizing the low pressure, high velocity flow in the plume, this secondary structure entrains a secondary mass flow to increase the mass flow of the propulsion system. Rocket engine nozzle ejectors must be designed with the high supersonic conditions associated with rocket engines. These designs rely on the numerical process described in this paper.
ContributorsGibson, Gaines Sullivan (Author) / Wells, Valana (Thesis director) / Takahashi, Timothy (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-05
Description
The purpose of this project is to determine the feasibility of a water tunnel designed to meet certain constraints. The project goals are to tailor a design for a given location, and to produce a repeatable design sizing and shape process for specified constraints. The primary design goals include a 1 m/s flow velocity in a 30cm x 30cm test section for 300 seconds. Secondary parameters, such as system height, tank height, area contraction ratio, and roof loading limits, may change depending on preference, location, or environment. The final chosen configuration is a gravity fed design with six major components: the reservoir tank, the initial duct, the contraction nozzle, the test section, the exit duct, and the variable control exit nozzle. Important sizing results include a minimum water weight of 60,000 pounds, a system height of 7.65 meters, a system length of 6 meters (not including the reservoir tank), a large shallow reservoir tank width of 12.2 meters, and height of 0.22 meters, and a control nozzle exit radius range of 5.25 cm to 5.3 cm. Computational fluid dynamic simulation further supports adherence to the design constraints but points out some potential areas for improvement in dealing with flow irregularities. These areas include the bends in the ducts, and the contraction nozzle. Despite those areas recommended for improvement, it is reasonable to conclude that the design and process fulfill the project goals.
ContributorsZykan, Brandt Davis Healy (Author) / Wells, Valana (Thesis director) / Middleton, James (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-05
Description
The objective of this project is to design an indraft supersonic wind tunnel that is safe and comparatively simple to construct. The processes and methodology of design are discussed. As with every supersonic wind tunnel, the critical components are the nozzle, diffuser, and the means of achieving the pressure differential which drives the flow. The nozzle was designed using method of characteristics (MOC) and a boundary layer analysis experimental proven on supersonic wind tunnels [5]. The diffuser was designed using the unique design features of this wind tunnel in combination with equations from Pope [7]. The pressure differential is achieved via a vacuum chamber behind the diffuser creating a pressure differential between the ambient air and the low pressure in the tank. The run time of the wind tunnel depends on the initial pressure of the vacuum tank and the volume. However, the volume of the tank has a greater influence on the run time. The volume of the tank is not specified as the largest tank feasible should be used to allow the longest run time. The run time for different volumes is given. Another method of extending the run duration is added vacuum pumps to the vacuum chamber. If these pumps can move a sufficient mass out of the vacuum chamber, the run time can be significantly extended. The mounting design addresses the loading requirements which is closely related to the accuracy of the data. The mounting mechanism is attached to the rear of the model to minimize shockwave interference and maximize the structural integrity along the direction with the highest loading. This mechanism is then mounted to the bottom of the wind tunnel for structural rigidity and ease of access.
ContributorsWall, Isaiah Edward (Author) / Wells, Valana (Thesis director) / Kshitij, Abhinav (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This project aims to study the relationship between model input parameters and model output accuracy of the Tool for Automation of Computational Aerodynamics of Airfoils (TACAA). The input parameters of study are Mach number and Reynolds number, and inputs are tested through three flight speed regimes and from laminar to turbulent flow. Each of these input parameters are tested for the NACA 0012 and SC-1095 airfoils to ensure that the accuracy is similar regardless of geometric complexity. The TACAA program was used to run all simulation testing, and its overall functionality is discussed. The results gathered from the preliminary testing showed that the spread of variable input data points caused data gaps in the transonic regime results, which provided motivation to conduct further testing within the transonic region for both airfoils. After collecting all TACAA results, data from wind tunnel testing was compiled to compare. The comparison showed that (1) additional testing would be necessary to fully assess the accuracy of the results for the SC-1095 airfoil and (2) TACAA is generally accurate for compressible, turbulent flows.
ContributorsKuang, Joyce (Co-author) / Stickel, Hannah (Co-author) / Wells, Valana (Thesis director) / Duque, Earl (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
During my fourth year at Arizona State University, I enrolled in two capstone projects while working towards my
undergraduate degree in aerospace engineering. The first of the two team projects was an aerospace capstone: Design of
Autonomous Aircraft Systems. The second being a capstone project based out of Arizona State’s design school:
Innovation Space. The purpose of this dual enrollment was to compare and contrast the two product development projects,
in hopes to recommend a course of action to engineers younger than myself who are presented the option of multiple
capstones. This report will elaborate on three areas of engineering design and how they were realized in these projects.
These 3 topics are product development and its effect on design to manufacture, design feature creep, and technical vs
non-technical design. After considering the pros and cons of both capstone projects and their relation to the three main
topics of this report, it was decided that individuals who are motivated to become the best engineers they can be upon
graduating from an undergraduate program, they should find the time to take both capstone courses. Both Design of
Autonomous Aircraft Systems and Innovation Space present opportunities to create new ways of engineering thinking, all
of which will be necessary for an engineer to succeed in his/her first years in industry.
undergraduate degree in aerospace engineering. The first of the two team projects was an aerospace capstone: Design of
Autonomous Aircraft Systems. The second being a capstone project based out of Arizona State’s design school:
Innovation Space. The purpose of this dual enrollment was to compare and contrast the two product development projects,
in hopes to recommend a course of action to engineers younger than myself who are presented the option of multiple
capstones. This report will elaborate on three areas of engineering design and how they were realized in these projects.
These 3 topics are product development and its effect on design to manufacture, design feature creep, and technical vs
non-technical design. After considering the pros and cons of both capstone projects and their relation to the three main
topics of this report, it was decided that individuals who are motivated to become the best engineers they can be upon
graduating from an undergraduate program, they should find the time to take both capstone courses. Both Design of
Autonomous Aircraft Systems and Innovation Space present opportunities to create new ways of engineering thinking, all
of which will be necessary for an engineer to succeed in his/her first years in industry.
ContributorsEll, Samuel Leo (Author) / Hedges, Craig (Thesis director) / Kuhn, Anthony (Committee member) / Industrial, Systems & Operations Engineering Prgm (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This paper presents the design of a pneumatic actuator for a soft ankle-foot orthosis, called the Multi-material Actuator for Variable Stiffness (MAVS). This pneumatic actuator consists of an inflatable soft fabric actuator fixed between two layers of rigid retainer pieces. The MAVS is designed to be integrated with a soft robotic ankle-foot orthosis (SR-AFO) exosuit to aid in supporting the human ankle in the inversion/eversion directions. This design aims to assist individuals affected with chronic ankle instability (CAI) or other impairments to the ankle joint. The MAVS design is made from compliant fabric materials, layered and constrained by thin rigid retainers to prevent volume increase during actuation. The design was optimized to provide the greatest stiffness and least deflection for a beam positioned as a cantilever with a point load. The design of the MAVS took into account passive stiffness of the actuator when combining rigid and compliant materials so that stiffness is maximized when inflated and minimal when passive. An analytic model of the MAVS was created to evaluate the effects in stiffness observed by varying the ratio in length between the rigid pieces and the soft actuator. The results from the analytic model were compared to experimentally obtained results of the MAVS. The MAVS with the greatest stiffness was observed when the gap between the rigid retainers was smallest and the rigid retainer length was smallest. The MAVS design with the highest stiffness at 100 kPa was determined, which required 26.71 ± 0.06 N to deflect the actuator 20 mm, and a resulting stiffness of 1,335.5 N/m and 9.1% margin of error from the model predictions.
ContributorsHertzell, Tiffany (Author) / Lee, Hyunglae (Thesis director) / Sugar, Thomas (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Accurate pointing is essential for any space mission with an imaging payload. The Phoenix Cubesat mission is being designed to take thermal images of major US cities from Low Earth Orbit in order to study the Urban Heat Island effect. Accurate pointing is vital to ensure mission success, so the satellite's Attitude Determination and Control System, or ADCS, must be properly tested and calibrated on the ground to ensure that it performs to its requirements. A commercial ADCS unit, the MAI-400, has been selected for this mission. The expected environmental disturbances must be characterized and modeled in order to inform planning the operations of this system. Appropriate control gains must also be selected to ensure the optimal satellite response. These gains are derived through a system model in Simulink and its response optimization tool, and these gains are then tested in a supplier provided Dynamic Simulator.
ContributorsWofford, Justin Michael (Author) / Bowman, Judd (Thesis director) / Jacobs, Daniel (Committee member) / School of Earth and Space Exploration (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This paper studies the history and development of ion propulsion systems and survey past, present, and developing technology with their applications to space missions. This analysis addresses the physical design parameters and process that is a part of designing and optimizing a gridded ion thruster. It also identifies operational limits that may be associated with solar-powered ion propulsion systems and posits plausible solutions or alternatives to remedy such limitations. These topics are presented with the intent of reviewing how ion propulsion technology evolved in its journey to develop to today's systems, and to facilitate thought and discussion on where further development of ion propulsion systems can be directed.
ContributorsTang, Justine (Author) / White, Daniel (Thesis director) / Dahm, Werner (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Prosthetic sockets are a static interface for dynamic residual limbs. As the user's activity level increases, the volume of the residual limb decreases by up to 11% and increases by as much as 7% after activity. Currently, volume fluctuation is addressed by adding/removing prosthetic socks to change the profile of the residual limb. However, this is time consuming. These painful/functional issues demand a prosthetic socket with an adjustable interface that can adapt to the user's needs. This thesis presents a prototype design for a dynamic soft robotic interface which addresses this need. The actuators are adjustable depending on the user's activity level, and their structure provides targeted compression to the soft tissue which helps to limit movement of the bone relative to the socket. The engineering process was used to create this design by defining system level requirements, exploring the design space, selecting a design, and then using testing/analysis to optimize that design. The final design for the soft robotic interface meets the applicable requirements, while other requirements for the electronics/controls will be completed as future work. Testing of the prototype demonstrated promising potential for the design with further refinement. Work on this project should be continued in future research/thesis projects in order to create a viable consumer product which can improve lower limb amputee's quality of life.
ContributorsHolmes, Breanna Swift (Author) / Zhang, Wenlong (Thesis director) / Polygerinos, Panagiotis (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Active pixel sensors hold a lot of promise for space applications in star tracking because of their effectiveness against radiation, small size, and on-chip processing. The research focus is on documenting and validating ground test equipment for these types of sensors. Through demonstrating the utility of a commercial sensor, the research will be able to work on ensuring the accuracy of ground tests. This contribution allows for future research on improving active pixel sensor performance.
ContributorsDotson, Breydan Lane (Author) / White, Daniel (Thesis director) / Jansen, Rolf (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05