Innovative Climate Change Emissions Reduction

Fair: 2023 Mercer Science and Engineering Fair
Event: Senior Division 2023
Category: General Engineering
Student: Charlotte Michaluk
Table: ENG6
Experimentation location: Home
Regulated Research (Form 1c): No
Project continuation (Form 7): Yes

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Abstract:

Bibliography/Citations:

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Bordogna, G., Muggiasca, S., Giappino, S., Belloli, M., Keuning, J. A., Huijsmans, R. H., & van‘t Veer, A. P. (2019). Wind-tunnel experiments on a large-scale Flettner Rotor. Lecture Notes in Civil Engineering, 110–123. https://doi.org/10.1007/978-3-030-12815-9_9

 

Boukhezzar, B., & Siguerdidjane, H. (2010). Comparison between linear and nonlinear control strategies for Variable Speed Wind Turbines. Control Engineering Practice, 18(12), 1357–1368. https://doi.org/10.1016/j.conengprac.2010.06.010

 

Buitendijk, M. (2020, July 7). Video: The forces that caused the MSC Zoe to lose containers explained: SWZ: Maritime. SWZ. Retrieved March 17, 2021, from https://swzmaritime.nl/news/2020/07/02/video-the-forces-that-caused-the-msc-zoe-to-los e-containers-explained/

 

Chopra, K. (2021, September 27). What is parametric rolling in container ships? Marine Insight.

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Copuroglu, H. I., & Pesman, E. (2018). Analysis of Flettner rotor ships in Beam Waves.

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Dai, S.-L., Wang, M., & Wang, C. (2016). Neural learning control of marine surface vessels with guaranteed transient tracking performance. IEEE Transactions on Industrial Electronics, 63(3), 1717–1727. https://doi.org/10.1109/tie.2015.2504553

 

De Marco, A., Mancini, S., Pensa, C., Calise, G., & De Luca, F. (2016). Flettner rotor concept for Marine applications: A systematic study. International Journal of Rotating Machinery, 2016, 1-12. doi:10.1155/2016/3458750

 

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Flettner, A. (1926). The story of the rotor. New York: F.O. Willhofft.

 

Fossen, T.I.. Guidance and Control of Ocean Marine Vehicles. John Wiley and Sons Ltd, New York, 1994.

 

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Fossen, T. I. (2005). A nonlinear unified state-space model for ship maneuvering and control in a seaway. Department of Engineering Cybernetics Norwegian University of Science and Technology. NO-7491 Trondheim, Norway

 

Gallucci, M. (2018, June 28). At last, the shipping industry Begins cleaning up its dirty fuels.

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Herzog, H. O. (1925). More facts about the Flettner rotor ship. Scientific American, 132(2), 82-83. doi:10.1038/scientificamerican0225-82

 

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Ibrahim, R. A., & Grace, I. M. (2010). Modeling of ship roll dynamics and its coupling with heave and pitch. Mathematical Problems in Engineering, 2010, 1–32. https://doi.org/10.1155/2010/934714

 

HEARST HOME BOOKS. (2021). Chapman piloting & seamanship.

 

Himeno, Y., “Prediction of Ship Roll Damping-State of the Art”, Research Project Report No.

239, University of Michigan, 1981.

 

Ikeda, Y., K. Komatsu, Y. Himeno and N. Tanaka (1976). On Roll Damping Force of Ship: Effects of Friction of Hull and Normal Force of Bilge Keels. Journal of the Kansai Society of Naval Architects 142, 54–66.

 

Ikeda, Y., Himeno, Y. and Tanaka, N., “A Prediction Method for Ship Roll Damping”, Report

 

No. 00405 of Department of Naval Architecture, University of Osaka Prefecture, 1978.

 

INTERNATIONAL MARITIME ORGANIZATION. (2007, January 11). Dated 11 January

2007, revised guidance to the ... - gov.uk. REVISED GUIDANCE TO THE MASTER FOR AVOIDING DANGEROUS SITUATIONS IN ADVERSE WEATHER AND SEA

CONDITIONS. Retrieved from https://assets.publishing.service.gov.uk/media/5e1dc8b140f0b610fcf63735/2020-2-CMA CGMGWashington_Annexes.pdf

 

Julià, E., Tillig, F., & Ringsberg, J. W. (2020). Concept design and performance evaluation of a Fossil-Free operated cargo ship with unlimited range. Sustainability, 12(16), 6609. doi:10.3390/su12166609

 

Katayama, T., Yoshioka, Y., Kakinoki, T., Miyamoto, S., & Ikeda, Y. (2019). Some topics for estimation of bilge keel component of roll damping. Contemporary Ideas on Ship Stability, 131–150. https://doi.org/10.1007/978-3-030-00516-0_8

 

Kianejad, S. S., Enshaei, H., Duffy, J., & Ansarifard, N. (2019). Prediction of a ship roll added mass moment of inertia using numerical simulation. Ocean Engineering, 173, 77–89. https://doi.org/10.1016/j.oceaneng.2018.12.049

 

Lack, D. A., Corbett, J. J., Onasch, T., Lerner, B., Massoli, P., Quinn, P. K., . . . Williams, E. (2009). Particulate emissions from commercial shipping: Chemical, physical, and optical properties. Journal of Geophysical Research, 114. doi:10.1029/2008jd011300

 

Liu, R., Xiang, Z. Q., Wang, Y. B., & Li, F. (2021). PSO-PID Control Strategy for ship anti roll slider device under the influence of long peak wave seas. Journal of Physics: Conference Series, 2029(1), 012086. https://doi.org/10.1088/1742-6596/2029/1/012086

 

Lloyd’s Register’s Ship Performance Group. (2020, January 17). Flettner Savings Calculator.

Retrieved from https://flettner.lr.org/#

 

Mason, H. (2020, November 23). Modernizing the mechanical rotor sail. Retrieved October 14th, 2021, from

https://www.compositesworld.com/articles/modernizing-the-mechanical-rotor-sail-

 

Michaluk, C (2021). Innovative Climate Change Emissions Reduction: The Cargo Ship Flettner Rotor Centrifugal Vortex Exhaust Scrubber. Submission to Regeneron International Science & Engineering Fair (ISEF)

 

Muller, M., Gotting, M., Peetz, T., Vahs, M., & Wings, E. (2019). An intelligent assistance system for controlling wind-assisted ship propulsion systems. 2019 IEEE 17th International Conference on Industrial Informatics (INDIN). https://doi.org/10.1109/indin41052.2019.8972271

 

News, W. (2019, October 24). Norsepower rotor Sails Achieve 8.2% of fuel savings ON Maersk pelican. Retrieved November 10, 2021, from

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maersk-pelican/

 

Newton, I. (1687) Philosophiae Naturalis Principia Mathematica. Londini, Jussu Societatis Regiæ ac Typis Josephi Streater. Prostat apud plures Bibliopolas. Anno. [Pdf] Retrieved from the Library of Congress, https://www.loc.gov/item/28020872/.

 

Nourmohammadi, F., Jumabayev, A., & Wings, E. (2021). Anomaly detection in the time series data from Fehn Pollux ship with Eco Flettner Rotor. 2021 IEEE 19th International Conference on Industrial Informatics (INDIN). https://doi.org/10.1109/indin45523.2021.9557422

 

Norsepower. (2019, October 24). Norsepower rotor Sails Achieve 8.2% of fuel savings ON Maersk pelican. From

https://www.offshore-energy.biz/norsepower-rotor-sails-achieve-8-2-of-fuel-savings-on- maersk-pelican/

 

O'Hanlon, J. F., & McCauley, M. E. (1973). Motion sickness incidence as a function of the frequency and acceleration of vertical sinusoidal motion. https://doi.org/10.21236/ad0768215

 

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https://www.oecd.org/ocean/topics/ocean-shipping/#:~:text=The%20main%20transport% 20mode%20for,transport%20arteries%20for%20global%20trade.

 

Panama Canal extends max length and increases draft for Neopanamax Locks. American Journal of Transportation. (2021, June 15). Retrieved December 17, 2021, from https://ajot.com/news/panama-canal-extends-max-length-and-increases-draft-for-neopana max-locks

 

Parametric Rolling Movement. Skuld.com. (n.d.). Retrieved December 17, 2021, from https://www.skuld.com/topics/cargo/containers/parametric-rolling-movement/#:~:text=Th e%20phenomenon%20known%20as%20Parametric,flared%20fore%20and%20aft%20de cks

 

Perez, Tristan, Smogeli, Oyvind, Fossen, Thor, & Sorensen, A J (2006) An overview of the Marine Systems Simulator (MSS): A simulink toolbox for marine control systems. Modeling, Identification and Control, 27(4), pp. 259-275.

 

Perez, T. (2005). Ship motion control. Springer-Verlag London Limited.

 

Peşman, Emre & Bayraktar, Deniz & Taylan, Metin. (2013). INFLUENCE OF DAMPING ON THE ROLL MOTION OF SHIPS.

 

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Retrieved from https://github.com/rfetick/MPU6050_light

 

Seakeeping Committee of the 28th ITTC. (2017). ITTC Quality System Manual Recommended Procedures and Guidelines Procedure, Seakeeping Experiments. In ITTC Quality Systems Manual. International Towing Tank Conference.

 

Sen, D. T., Vinh, T.C., (2016). Determination of Added Mass and Inertia Moment of Marine Ships Moving in 6 Degrees of Freedom. International Journal of Transportation Engineering and Technology, Volume 2, Issue 1, March 2016, Pages: 8-14

 

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Shi, Y., Shen, C., Fang, H., & Li, H. (2017). Advanced control in Marine Mechatronic Systems: A survey. IEEE/ASME Transactions on Mechatronics, 22(3), 1121–1131. https://doi.org/10.1109/tmech.2017.2660528

 

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Timberwolf Rotor Sails. Norsepower. (2020). https://www.norsepower.com/tanker/.

 

US Department of Commerce, N. O. A. A. (2019, August 9). Wind, Swell and rogue waves.

NWS JetStream. Retrieved December 17, 2021, from https://www.weather.gov/jetstream/waves

 

United States Environmental Protection Agency, O. (2011, November). Exhaust Gas Scrubber Washwater Effluent. From https://www3.epa.gov/npdes/pubs/vgp_exhaust_gas_scrubber.pdf

 

Uyar, E., Alpkaya, A. T., & Mutlu, L. (2016). Dynamic modelling, investigation of manoeuvring capability and navigation control of a cargo ship by using MATLAB Simulation. IFAC-PapersOnLine, 49(3), 104–110. https://doi.org/10.1016/j.ifacol.2016.07.018

 

Vasilescu, M.-V., Voicu, I., Panait, C., & Ciucur, V.-V. (2020). Influence of four modern Flettner rotors, used as wind energy capturing system, on container ship stability. E3S Web of Conferences, 180, 02003. https://doi.org/10.1051/e3sconf/202018002003

 

Walker TR, Adebambo O, Del Aguila Feijoo MC, Elhaimer E, Hossain T, Edwards SJ, Morrison CE, Romo J, Sharma N, Taylor S, Zomorodi S (2019). "Environmental Effects of Marine Transportation". World Seas: An Environmental Evaluation. pp. 505–530.

 

Wang, N., Er, M.J., (2014). Adaptive neural network control of a fully actuated marine surface vessel with multiple output constraints. IEEE Transactions on Control Systems Technology, 22(4), 1536–1543. https://doi.org/10.1109/tcst.2013.2281211

 

Wei Jingyi, & Fan Yinhai. (n.d.). A fuzzy PID Controller for ship course based on engineering tuning methods. 2001 International Conferences on Info-Tech and Info-Net. Proceedings (Cat. No.01EX479). https://doi.org/10.1109/icii.2001.983847

 

Wings, E., Reck, S., Boomgaarden, H., Nourmohammadi, F., & Peetz, T. (2022).

Implementing a low-cost control unit network focusing on data collection and Flettner Rotor Control. 2022 IEEE International Conference on Industry 4.0, Artificial Intelligence, and Communications Technology (IAICT). https://doi.org/10.1109/iaict55358.2022.9887390

 

Modeling and control programming performed in MathWorks MATLAB and Simulink software. Statistical tests performed in Excel Analysis ToolPak, All figures and images by author.


Additional Project Information

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Research Plan:

Rationale:

This is an exciting time for cargo ship naval architecture as technologies as new as AI and as old as wind power converge to reduce our transportation climate change footprint.

Despite electrification of vehicles, optimistic attempts to “leave it in the ground,” and a fossil fuel shift to plastic, petroleum fuels will be part of our lives for decades, and with it the heavy fuel oil byproducts of gasoline, diesel, and jet fuel. This dirty residual fuel is difficult to further refine and thus finds a use powering our cargo ship fleet, which are coming under increasing scrutiny as they contribute 4% to global climate change contributions. (2020 IEC rule)

Our desire to use raw materials from around the globe or take advantage of relative efficiencies in production shows no sign of slowing, therefore our global cargo fleet consisting of over 100,000 vessels will persist.

A novel centrifugal vortex scrubber integrated into a Flettner rotor creates a hybrid wind and fossil fuel powered vessel that cleans exhaust while generating propulsive power, that more than compensates for the engine power loss through the scrubber, and the initial capital investment.

Seakeeping is the ability of a vessel to limit motion due to waves and weather, resulting in increased crew comfort, safety, and performance. Improving seakeeping broadens the operating envelope of the vessel, adding significant value by allowing vessel goals to be achieved in a wider range of weather conditions.

Ships such as research vessels and cruise ships where crew and passenger comfort is a priority are often fitted with active seakeeping measures such as hydraulically controlled hydrofoils, gyroscopes, or powerful pumps transferring water between port and starboard tanks as the ship rolls. On a ship, all of these active systems consume valuable cargo space and energy, and require costly hardware and hull appendages. This makes them cost prohibitive, especially to developing economies.

Enhancing this Flettner Vortex Scrubber with active seakeeping control for crew comfort and efficiency would make this climate change mitigation technology an even more attractive investment for ship owners and operators, by allowing the same rotor and scrubber hardware to also act as an active seakeeping system.

The goal of the research was to determine which control system architecture best optimizes Flettner rotor seakeeping capability by reducing cargo ship transverse roll angle and acceleration. A mathematical model of a ship and Flettner rotors were tested with different control architectures. Experimental design and simulations were selected as the overarching method. Experimental design and simulation are common among naval architecture and marine engineering projects such as this one. Projects often rely to a great extent on simulation in software due to the high cost of testing physical scale models in

 

towing tanks or wave pools, and the high cost and unpredictable conditions of sea trials. From a literature review, two control system architectures were selected: linear proportional integral derivative (PID) and model predictive control (MPC). Following the convention of experimental design, a control group was included to be able to establish a causal relationship between the independent variable of control system architecture and the dependent variables that indicate seakeeping performance. The data collected was primarily quantitative. MathWorks MATLAB Simulink was selected as the simulation software because of its popularity and control system capabilities. Simulations allow for time efficiency, a greater range of testing environments, and convenient control system modification.

This research created a mathematical model of the ship and waves in Mathworks Simulink software. The ship was modeled with a buoyancy, mass distribution, and hull shape approximating a neopanamax cargo ship. Two types of feedback control algorithms were selected for comparison. Linear PID is standard across multiple industries for feedback control, and included by the Seakeeping Committee of the 28th International Towing Tank Conference (2017), for rudder control in guidance systems. A tactical model predictive control (MPC), similar to that described in Perez (2005), was also selected. MPC inherently handles feedforward and decoupling signals using a model of the physical system to optimize a cost function in a time window.

 

Design Goals and Criteria:

  1. Create a mathematical model of cargo ship transverse roll.
  2. Program and tune PD and MPC control algorithms for comparison.
  3. Reduce transverse roll sufficiently to expand vessel operating envelope.
  4. Manage and reduce parametric roll with resonant frequency shift. Parametric roll can cause loss of cargo containers. An economic loss to the carrier, and a safety risk to other mariners.
  5. Reduce harmful cargo ship emissions by optimizing active seakeeping to the Flettner Vortex Scrubber value proposition, making this climate change emissions-reducing technology a compelling business case for ship owners, operators, and crew.

 

Design Constraints:

  1. Wave period and amplitude scaled to open ocean.
  2. Prototype mass distribution, buoyancy, and hull shape must approximate neopanamax cargo ship.
  3. Prototype ship hull must be watertight to avoid motor damage.
  4. Maintain stability within United States Coast Guard (USCG), International Maritime Organization (IMO), Safety of Life at Sea (SOLAS) and underwriters’ hull stability limits.

 

Research Question:

Will classical or modern control theory architecture best optimize Flettner rotor sail seakeeping capability by reducing cargo ship transverse roll?

 

Procedures:

 

Creating mathematical model of cargo ship transverse roll

  1. Create a mathematical model of cargo ship transverse roll by applying Newton's Second Law, modeling as a Mass Spring Damper system, and defining external moments on the ship.
    1. Add damping coefficient for viscous drags proportional to velocity
    2. Add damping coefficient for pressure drags proportional to velocity squared
    3. Include roll-added inertia by calculating the roll added mass and adding to the physical mass.
    4. Expand formula for buoyant force generating moment arm based on free body diagram of floating cargo ship in the y-z plane, rotating about x axis.
    5. Program cargo ship transverse roll model in Simulink.
  2. Determine input values for
    1. Neopanamax cargo ship mass from literature references
    2. Acceleration due to gravity from literature references
    3. Average density of seawater from literature references
    4. Metacentric height from literature references
    5. Viscous drags damping coefficient from AFVS prototype data
    6. Pressure drags damping coefficient from AFVS prototype data
    7. Inertia calculated from literature references
    8. Roll Added Inertia calculated from literature references

 

Programming PD controller and tuning

  1. Select Proportional Differential (PD) controller rather than Proportional Integral Differential controller due to comparability to MPC without integrator.
  2. Linearize mathematical model of cargo ship transverse roll.
    1. Identify the nonlinear dynamics.
    2. Apply linear approximations based on operating point.
  3. Use a Laplace transform to derive the system’s transfer function in the frequency domain.
  4. Formulate closed loop feedback controller transfer function T(S) which defines relationship between input and output.
    1. c(s)= u(s)/E(s)= kp + ki/s +kds
    2. T(s)= (c(s)*g(s))/(1 + (c(s)*g(s)))
  5. Determine poles from transfer function denominator to understand stability and dynamic behavior of the system consisting of neopanamax cargo ship transverse roll, and AFVSs with PD controller.
  6. Program PD into cargo ship transverse roll model in Simulink.
  7. Tune PD controller based on physical constraints of AFVSs operating on a neopanamax cargo ship.

 

Programming MPC controller and tuning

 

  1. Recognize that the cargo ship transverse roll model is a second order differential equation.
  2. Linearize cargo ship transverse roll model.
  3. Define A, B, and C matrices for cargo ship transverse roll.
  4. Define a continuous state-space in MATLAB to create AFVS MPC controller.
  5. Convert continuous AFVS MPC state-space to discrete state-space
  6. Define a quadratic cost function with Q and R matrices for tuning MPC controller for AFVS seakeeping.
  7. Program formula for unconstrained linear MPC control law for AFVS in MATLAB.
  8. Determine eigenvalues to understand stability and dynamic behavior of the system consisting of neopanamax cargo ship transverse roll, and AFVSs with MPC controller.
  9. Program MPC in Simulink. Simulink implementation of the unconstrained linear MPC control law.
  10. Tune MPC controller based on physical constraints of AFVSs operating on a neopanamax cargo ship.

Risk and Safety:

Power tools will be properly used in a well-maintained workspace, while wearing appropriate clothing. Personal protective equipment will be appropriately used: safety glasses, N95 masks, hearing protection, carving gloves, utility gloves to protect from sharp edges, and nitrile gloves.

All wiring within 6 feet of water will be low voltage. 110 VAC appliances and enclosures will be UL / ETL certified. Electrical connections will be inspected by an electrician prior to use and testing to ensure they are in excess of National Electric code. 110 VAC appliances used during testing will be powered through a Ground Fault Current Interrupt (GFCI) as well as a safety switch that disconnects both line and neutral. All electrical devices will be properly grounded. Low voltage marine wire will be used.

 

Data Analysis:

Data will be gathered and analyzed using specialized statistical software. Results will be analyzed for statistical significance.

Questions and Answers

Hypothesis/Purpose - describes why you did your project

The goal of the research was to determine whether classical or modern control theory architecture best optimizes Flettner rotor sail seakeeping capability by reducing cargo ship transverse roll. This goal was developed because Flettner rotor propulsion shows immense promise for reducing cargo ship emissions and can be made more attractive to ship owners and operators by best leveraging their seakeeping capabilities. According to my review of literature, control system design has not been researched for propulsion Flettner rotor seakeeping.

 

Research Plan - describes how you prepared to do the project

See separate file

 

Bibliography/Citations

See separate file

 

What was the major objective of your project and what was your plan to achieve it?

The major objective of my project was to investigate PID and MPC Control for my Active Flettner Vortex Scrubber to gain insight on how Flettner rotor control can be used to best take advantage of the seakeeping capabilities of rotor sails.

My plan was to create a mathematical model of the cargo ship and waves in Mathworks Simulink software. The ship was modeled with a buoyancy, mass distribution, and hull shape approximating a neopanamax cargo ship. Two types of feedback control algorithms were selected for comparison. Linear PID is standard across multiple industries for feedback control, and included by the Seakeeping Committee of the 28th International Towing Tank Conference (2017), for rudder control in guidance systems. A model predictive control (MPC), similar to that described in Perez (2005), was also selected. MPC inherently handles feedforward and decoupling signals using a model of the physical system to optimize a cost function in a receding time window. Compared to the Linear Quadratic Gaussian (LQG) method described by Boukhezzar & Siguerdidjane (2010), MPC has a more complex and locally optimal response.

MPC also functions well when a nonlinear system moves away from a linearized operating point. Both are important for seakeeping.

To achieve the goal of developing the optimal control system for adding seakeeping functionality, my plan was to complete development of the following:

 

  1. Create a mathematical model of cargo ship transverse roll
  2. Determine input values for a neopanamax cargo ship
  3. Program PD controller
  4. Tune PD controller for optimal seakeeping.
  5. Program MPC controller
  6. Tune MPC controller for optimal seakeeping.

 

  1. Compare seakeeping performance of tuned controllers

 

 

  1. Was that goal the result of any specific situation, experience, or problem you encountered?

 

Being at sea, having been a lifelong sailor, I have observed many cargo ships enter harbors and clearly see the amount of particulate matter coming from them and can only imagine the climate change emissions that are not visible.

After working on further research on this area and spending a large part of the summer on the ocean, I have become even more aware of these problems and the importance of finding solutions.

I can understand why people who live near harbors see cargo ship emissions as even more of a critical issue particularly with regards to health.

Ships began using oil as an energy source around 1900, however use of exhaust scrubbers on ships was very limited until recently, due to light regulation. In 1973 the regulation of pollution in international waters was first discussed at the first marine pollution convention, or MARPOL. Sulfur emissions restrictions did not go into effect until 2012 with a 3.5% sulfur cap. In 2020 this cap was reduced to 0.5%, prompting ships to either consume less residual fuels, or install scrubbers. Because of this, it seems like scrubber technology is designed around

land-based applications like power generating stations that have been more regulated, and not marine applications. Heavy fuel oil is a residual product of petroleum refining for gasoline and diesel. Marine fuel oil engines are a mature, low cost, and reliable technology. I feel that marine exhaust scrubbers and cargo ship wind power are very important technologies to advance.

Large ships contribute to 4% of global climate change emissions. According to the Yale School of the Environment, we are just learning that the combustion products of heavy fuel oil are especially noxious pollutants which can travel hundreds of miles leading to roughly 7.6 million childhood asthma cases and 150,000 premature deaths annually.

 

  1. Were you trying to solve a problem, answer a question, or test a hypothesis?

 

I was trying to do all three. I was trying to solve the problem of climate change by reducing cargo ship emissions. I was trying to answer questions regarding applying scientific principles to design a new solution. I was testing the hypothesis that programming Model Predictive Control (MPC) to optimize the seakeeping functionality of my Active Flettner Vortex Scrubber hardware would be more effective than programming a Proportional Integral Derivative (PID) control.

 

 

  1. What were the major tasks you had to perform in order to complete your project?

 

The major tasks involved were the following:

 

    1. Create a mathematical model of cargo ship transverse roll

 

    1. Determine input values for a neopanamax cargo ship based upon data published in literature and data gathered from my prototype neopanamax cargo ship.
    2. Program PD controller in MATLAB and Simulink.
    3. Tune PD controller for optimal seakeeping.
    4. Program MPC controller in MATLAB and Simulink.
    5. Tune MPC controller for optimal seakeeping.
    6. Compare seakeeping performance of tuned controllers.

 

In order to complete my project, I needed to further advance my programming skills. I used online resources, MATLAB Onramp, Simulink Onramp, and Codecademy.

 

a. For teams, describe what each member worked on.

 

This was not a team project.

 

  1. What is new or novel about your project?

 

  1. Is there some aspect of your project's objective, or how you achieved it that you haven't done before?

 

I have never created a mathematical model of cargo ship transverse roll movement. I have never researched or programmed model predictive control. I had to learn linear algebra, MATLAB, and Simulink, as well as more control engineering in order to do this.

 

  1. Is your project's objective, or the way you implemented it, different from anything you have seen?

 

Yes, no indication of using Flettner rotor sails for seakeeping or the requisite control software was found in my literature review.

According to my review of literature, the idea of maintaining the same volume, same hardware and same drive system but adding a more sophisticated control system for the purpose of increasing Flettner rotor value through seakeeping capabilities has not yet been investigated. While PID and MPC are well established in the naval architecture and marine engineering body of knowledge, literature review did not reveal any investigation related to seakeeping capabilities of rotor sails, or the appropriate application of control theory for rotor sail seakeeping.

In addition to control systems, my research indicates that Flettner Rotors, also called rotor sails, used for capture of wind energy for ship propulsion, have not been designed or controlled in such a way to also act as active seakeeping systems, which is what I am developing in this project. The body of literature seems to be more focused on Flettner rotors in comparison to other wind power propulsion systems and optimizing Flettner rotor geometry for high coefficient of lift and structural integrity.

Note that stabilization systems using underwater foils or underwater flettner rotors do exist. This is a completely different application than Flettner rotors employed for wind propulsion

 

which are otherwise known as rotor sails. Stabilization systems using rotors and the Magnus effect do not serve any propulsion or efficiency purpose, are below the waterline, and require dedicated seakeeping hardware.

Ships such as research vessels and cruise ships where crew and passenger comfort is a priority are often fitted with active seakeeping measures such as hydraulically controlled hydrofoils, gyroscopes, or powerful pumps transferring water between port and starboard tanks as the ship rolls. On a ship, all of these active systems consume valuable cargo space and energy, and require costly hardware and hull appendages. This makes them cost prohibitive, especially to developing economies.

I have not seen any Flettner Rotors for capture of wind energy for ship propulsion also enhanced with functionality to use rotational speed control as an active seakeeping system.

I have not seen a proposal to utilize the volume inside Flettner Rotors. It seems that scrubber technology designed around land-based applications like power generating stations is being “cut-and-pasted” into new and retrofit marine applications due to increased pollution regulation in international waters.

My Flettner Vortex Scrubber recaptures unused shipboard volume and augments auxiliary wind propulsion in an innovative way for climate change emissions reduction and for an expanded vessel operating envelope.

 

  1. If you believe your work to be unique in some way, what research have you done to confirm that it is?

 

I performed a thorough literature review which included well in excess of 75 sources, including leading researchers in the field of ocean vessel hydrodynamics and motion control, and researchers specializing in Flettner rotor technology and the Magnus effect. No indication of using Flettner rotor sails for seakeeping or the requisite control software was surfaced.

I researched Flettner Rotors for capture of wind energy for ship propulsion and have not seen any that use rotational speed control as an active seakeeping system.

I researched shipboard systems with a focus on pollution reduction and have not seen any that combine engine exhaust scrubbers and Flettner Rotors.

I have never seen anything like this. The closest concept that I could find was a seakeeping method for using the rudder to control roll. This required heavier rudder bearings and drive system. According to my review of current literature, the addition of Flettner rotor controls for active seakeeping is a novel concept.

 

  1. What was the most challenging part of completing your project?

 

Deeply understanding the complex mathematics behind my model and controls was one of the most challenging and rewarding aspects of my project. It was very satisfying to be able to model and program system in MATLAB and Simulink by starting with the underlying mathematics rather than using preprogrammed blocks, as well as using Eigenvalues from matrices and poles from transfer functions to determine stability and response of a system

 

  1. What problems did you encounter, and how did you overcome them?

 

It was initially daunting to have to learn so many new things at once: control theory, some linear algebra, MATLAB and Simulink. I overcame this by being organized and resourceful. Initially I was intimidated by the equations in research papers, but breaking them down and working to understand each term one piece at a time was very helpful. I dedicated myself to really understand the mathematical dynamics of my system, and progress was very rewarding. This project took a lot of persistence and learning.

 

  1. What did you learn from overcoming these problems?

 

I learned that even when it feels like I am not making any progress, I am still moving forward, and as long as I stay focused, the next flash of insight could come at any time. With a large undertaking, there is a large impact. I feel that I have grown so much.

 

  1. If you were going to do this project again, are there any things you would you do differently the next time?

 

If I were to start this project over from the beginning, I may reconsider my decision to program the MPC controller from first principles rather than using the pre-programmed blocks in Simulink. I may also explore commercial naval architecture and marine engineering software for strip theory or panel models of vessels. However, I deeply appreciate the math that I learned by starting at the beginning.

Another improvement I would make is to position the motor higher above the bilge of the cargo ship test mule so that small leaks would be less likely to contact the motor. This would make the system more robust.

 

  1. Did working on this project give you any ideas for other projects?

 

Yes, this endeavor was my first time using mathworks MATLAB and simulink. I am excited about continuing explorations in this software, and have a long list of next steps and projects to explore!

I am fascinated by all of the engineering solutions that can be developed to make cargo shipping cleaner. There are so many concepts currently being explored, from capturing waste engine heat and generating electricity, to optimizing float plans for optimal weather, currents, and sea state.

I am especially interested in how recent advances in materials and machine learning technology can be used to apply wind power to today’s cargo ships.

I would love to use an oscilloscope to gain more precise control of the stepper motor.

 

  1. How did COVID-19 affect the completion of your project?

 

Due to COVID-19 I did not attend professional conferences in person where I could have received more feedback. However, I was flown to Albuquerque by the Department of Defense. I am grateful to the Department of Defense for the trip and opportunity to present and visit the

 

Kirtland Air Force Base, in Albuquerque, NM, and for the recognition of Major General Dr. Heather Pringle, Commander of the Air Force Research Laboratory.

I was also able to continue in a virtual mentorship program and gained feedback from an engineer at the Department of Defense.