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You searched for +publisher:"University of Texas – Austin" +contributor:("Acikmese, Behcet"). Showing records 1 – 2 of 2 total matches.

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University of Texas – Austin

1. Berning, Andrew Walter, Jr. Verification of successive convexification algorithm.

Degree: MSin Engineering, Aerospace engineering, 2016, University of Texas – Austin

In this report, I describe a technique which allows a non-convex optimal control problem to be expressed and solved in a convex manner. I then verify the resulting solution to ensure its physical feasibility and its optimality. The original, non-convex problem is the fuel-optimal powered landing problem with aerodynamic drag. The non-convexities present in this problem include mass depletion dynamics, aerodynamic drag, and free final time. Through the use of lossless convexification and successive convexification, this problem can be formulated as a series of iteratively solved convex problems that requires only a guess of a final time of flight. The solution’s physical feasibility is verified through a nonlinear simulation built in Simulink, while its optimality is verified through the general nonlinear optimal control software GPOPS-II. Advisors/Committee Members: Akella, Maruthi Ram, 1972- (advisor), Acikmese, Behcet (committee member).

Subjects/Keywords: Convex; Convexification; Optimization; Verification

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Berning, Andrew Walter, J. (2016). Verification of successive convexification algorithm. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/41579

Chicago Manual of Style (16th Edition):

Berning, Andrew Walter, Jr. “Verification of successive convexification algorithm.” 2016. Masters Thesis, University of Texas – Austin. Accessed September 21, 2020. http://hdl.handle.net/2152/41579.

MLA Handbook (7th Edition):

Berning, Andrew Walter, Jr. “Verification of successive convexification algorithm.” 2016. Web. 21 Sep 2020.

Vancouver:

Berning, Andrew Walter J. Verification of successive convexification algorithm. [Internet] [Masters thesis]. University of Texas – Austin; 2016. [cited 2020 Sep 21]. Available from: http://hdl.handle.net/2152/41579.

Council of Science Editors:

Berning, Andrew Walter J. Verification of successive convexification algorithm. [Masters Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/41579

2. Ambruș, Adrian Marius. Modeling and control of managed pressure drilling operations.

Degree: PhD, Mechanical Engineering, 2017, University of Texas – Austin

The upstream oil and gas industry has witnessed a marked increase in the number of wells drilled in areas with elevated subsurface formation pressures and narrow drilling margins. Managed Pressure Drilling (MPD) techniques have been developed to deal with the challenge of narrow margin wells, offering great promise for improved rig safety and reduced non-productive time. Automation of MPD operations can ensure improved control over wellbore pressure profiles, and there are several commercial solutions currently available. However, these automation efforts seldom take into account the uncertainty and complex dynamics inherent in subsurface environments, and usually assume ideally functioning sensors and actuators, which is rarely the case in real-world drilling operations. This dissertation describes a set of tools and methods that can form the basis for an automation framework for MPD systems, with specific focus on the surface back-pressure technique of MPD. Model-based control algorithms with robust reference tracking, as well as methods for detecting system faults and handling modeling uncertainty, are integrated with a novel multi-phase hydraulics model. The control system and event detection modules are designed using physics-based representations of the drilling processes, as well as models relating uncertain variables in a probabilistic fashion. Validation on high-fidelity simulation models is conducted in order to ascertain the effectiveness of the developed methods. Advisors/Committee Members: Oort, Eric van (advisor), Fernandez, Benito R. (advisor), Longoria, Raul (committee member), Barr, Ronald (committee member), Acikmese, Behcet (committee member), Ashok, Pradeepkumar (committee member).

Subjects/Keywords: Managed pressure drilling; Multi-phase hydraulic modeling; Robust control; Event detection

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ambruș, A. M. (2017). Modeling and control of managed pressure drilling operations. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/54113

Chicago Manual of Style (16th Edition):

Ambruș, Adrian Marius. “Modeling and control of managed pressure drilling operations.” 2017. Doctoral Dissertation, University of Texas – Austin. Accessed September 21, 2020. http://hdl.handle.net/2152/54113.

MLA Handbook (7th Edition):

Ambruș, Adrian Marius. “Modeling and control of managed pressure drilling operations.” 2017. Web. 21 Sep 2020.

Vancouver:

Ambruș AM. Modeling and control of managed pressure drilling operations. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2017. [cited 2020 Sep 21]. Available from: http://hdl.handle.net/2152/54113.

Council of Science Editors:

Ambruș AM. Modeling and control of managed pressure drilling operations. [Doctoral Dissertation]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/54113

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