Showing papers on "Propulsion published in 2022"

Hybrid power and propulsion systems for ships: Current status and future challenges

Abstract: Increasing environmental concerns are driving the shipping industry to take strict measures to deal with greenhouse gas emissions. International Maritime Organization drives the industry to find more efficient and environmentally friendly power systems. To mitigate harmful emissions, researches on marine alternative fuels, operational improvements like slow steaming or predictive maintenance, and additional emission abatement technologies are not sufficient. The use of electricity as the main energy vector is one of the ways to improve the shipping propulsion system's efficiency. In this study, power generation technologies, energy storage components, energy management systems, and hybrid propulsion topologies are reviewed. Diesel engines, fuel cells, solar and wind power as renewable energy sources are discussed as power generation units. On the energy storage side, batteries, supercapacitors, and flywheels are presented and described. Three common hybrid propulsion configurations, serial, parallel, and serial-parallel architectures are detailed with their pros and cons by highlighting commonly used energy management systems and optimization methods. Lastly, criteria for hybrid system selection are defined according to eight different ship types and assessed by providing a generic methodological approach. It is shown that electrical components and architectural design should be elaborated according to operational and architectural characteristics for ships. In short term, it is concluded that internal combustion engines are still the major hybridization element with different energy storage systems. New regulations on the mitigation of harmful emissions will accelerate the transition to hybrid power which is an important option for the ultimate zero-carbon shipping goal.

A Review of DC Shipboard Microgrids—Part I: Power Architectures, Energy Storage, and Power Converters

Abstract: Integrated power systems are popular in the shipbuilding industry. DC shipboard microgrids (dc-SMGs) have many advantages compared with ac ones in terms of system efficiency, operation flexibility, component size, and fault protection performance. Being in the exploring stage, dc-SMGs have several potential configurations with different system architectures and voltage levels. In a dc-SMG, functional blocks integrated include power generation modules (PGMs), propulsion system, high power loads, and pulsed loads specifically in naval ships. In modern ships, the PGMs include not only generators and fuel cells but also energy storage systems (ESSs), which cooperate with generators to improve the overall efficiency and reliability. High power electric converters are vital interfaces between the functional blocks and the dc distribution system. Rectifiers for generators take the tasks of dc bus voltage regulation and power sharing. Inverters for propulsion motors are responsible for the motor drive in different operating conditions. Bidirectional dc/dc converters for ESSs are used to provide supply-demand balance and voltage fluctuation mitigation. This article makes a comprehensive review of power architecture, functional blocks including electrical machines and energy storage, as well as power converters in dc shipboard power systems.

Self-Propulsion of Chemically Active Droplets

Abstract: Microscopic active droplets are able to swim autonomously in viscous flows. This puzzling feature stems from solute exchanges with the surrounding fluid via surface reactions or their spontaneous solubilization and from the interfacial flows resulting from these solutes’ gradients. Contrary to asymmetric active colloids, these isotropic droplets swim spontaneously by exploiting the nonlinear coupling of solute transport with self-generated Marangoni flows; such coupling is also responsible for secondary transitions to more complex individual and collective dynamics. Thanks to their simple design and their sensitivity to physico-chemical signals, these droplets are fascinating to physicists, chemists, biologists, and fluid dynamicists alike in analyzing viscous self-propulsion and collective dynamics in active-matter systems, developing synthetic cellular models, or performing targeted biomedical or engineering applications. I review here the most recent and significant developments of this rapidly growing field, focusing on the mathematical and physical modeling of these intriguing droplets, together with their experimental design and characterization. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 55 is January 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Overview on Digital Twin for Autonomous Electrical Vehicles Propulsion Drive System

Abstract: The significant progress in the electric automotive industry brought a higher need for new technological innovations. Digital Twin (DT) is one of the hottest trends of the fourth industrial revolution. It allows representing physical assets under various operating conditions in a low-cost and zero-risk environment. DTs are used in many different fields from aerospace to healthcare. However, one of the perspective applications of such technology is the automotive industry. This paper presents an overview of the implementation of DT technology in electric vehicles (EV) propulsion drive systems. A general review of DT technology is supplemented with main applications analysis and comparison between different simulation technologies. Primary attention is given to the adaptation of DT technology for EV propulsion drive systems.

Spinning-enabled wireless amphibious origami millirobot

Abstract: Wireless millimeter-scale origami robots that can locomote in narrow spaces and morph their shapes have recently been explored with great potential for biomedical applications. Existing millimeter-scale origami devices usually require separate geometrical components for locomotion and functions, which increases the complexity of the robotic systems and their operation upon limited locomotion modes. Additionally, none of them can achieve both on-ground and in-water locomotion. Here we report a magnetically actuated amphibious origami millirobot that integrates capabilities of spinning-enabled multimodal locomotion, controlled delivery of liquid medicine, and cargo transportation with wireless operation. This millirobot takes full advantage of the geometrical features and folding/unfolding capability of Kresling origami, a triangulated hollow cylinder, to fulfill multifunction: its geometrical features are exploited for generating omnidirectional locomotion in various working environments, including on unstructured ground, in liquids, and at air-liquid interfaces through rolling, flipping, and spinning-induced propulsion; the folding/unfolding is utilized as a pumping mechanism for integrated multifunctionality such as controlled delivery of liquid medicine; furthermore, the spinning motion provides a sucking mechanism for targeted solid cargo transportation. This origami millirobot breaks the conventional way of utilizing origami folding only for shape reconfiguration and integrates multiple functions in one simple body. We anticipate the reported magnetic amphibious origami millirobots have the potential to serve as minimally invasive devices for biomedical diagnoses and treatments.

High shear rate propulsion of acoustic microrobots in complex biological fluids

Abstract: Untethered microrobots offer a great promise for localized targeted therapy in hard-to-access spaces in our body. Despite recent advancements, most microrobot propulsion capabilities have been limited to homogenous Newtonian fluids. However, the biological fluids present in our body are heterogeneous and have shear rate–dependent rheological properties, which limit the propulsion of microrobots using conventional designs and actuation methods. We propose an acoustically powered microrobotic system, consisting of a three-dimensionally printed 30-micrometer-diameter hollow body with an oscillatory microbubble, to generate high shear rate fluidic flow for propulsion in complex biofluids. The acoustically induced microstreaming flow leads to distinct surface-slipping and puller-type propulsion modes in Newtonian and non-Newtonian fluids, respectively. We demonstrate efficient propulsion of the microrobots in diverse biological fluids, including in vitro navigation through mucus layers on biologically relevant three-dimensional surfaces. The microrobot design and high shear rate propulsion mechanism discussed herein could open new possibilities to deploy microrobots in complex biofluids toward minimally invasive targeted therapy.

Optimization-Based Power and Energy Management System in Shipboard Microgrid: A Review

Abstract: The increasing demands for reducing greenhouse emissions and improving fuel efficiency of marine transportation have presented opportunities for electric ships. Due to the complexity of multiple power resources coordination, varied propulsion loads, changeable economical, and environmental requirements, power/energy management system (PMS/EMS) becomes essential in both designing and operational processes. The existing literature on PMS/EMS can be categorized into rule-based and optimization-based approaches. Compared to the rule-based PMS/EMS, which relies heavily on human expertise, as well as predefined strategies and priorities, the optimization-based approaches can offer more efficient solutions and are more widely used nowadays. This article provides a comprehensive review of the marine optimization-based power/energy management system and discusses the future trends of PMS/EMS in ship power systems.

A review of architectures and control strategies of dual-motor coupling powertrain systems for battery electric vehicles

Abstract: With more and more stringent regulations related to emissions, the increasing requirement of energy conservation, and the growing concern for global warming, battery electric vehicles are gaining increasing popularity in the market and that may eventually supplant their counterparts, the internal combustion engine and hybrid electric vehicles. Currently, one can classify battery electric vehicles based on their propulsion type, namely: single-motor drive and multi-motor drive. In this paper, a review of architectures and control strategies for the dual-motor coupling propulsion system used in battery electric vehicles is presented. The paper describes different architectures, reviews the means of mechanical coupling and transmission, electromechanical configurations, and summarizes approaches to the control of this emerging class of battery electric vehicles. A comparison of the advantages and disadvantages of dual-motor coupling propulsion system technology for battery electric vehicles is highlighted, and research challenges and prospects are also discussed. This paper intends to serve as a state-of-the-art reference for researchers in the field of dual-motor coupling propulsion systems used in battery electric vehicle development, control, and optimization.

Development and Motion Control of Biomimetic Underwater Robots: A Survey

Abstract: Biomimetic underwater robots have attracted considerable research attention globally, owing to their quieter actuations, higher propulsion efficiency, and stronger maneuverability when compared with conventional underwater vehicles equipped with axial propellers. This article provides a comprehensive survey of current research in this field. First, we review the development status of biomimetic underwater robots in both body/caudal fin (BCF), median/paired fin (MPF), and their hybrid propulsion modes. Then, we outline the motion control methods employed in biomimetic underwater robots, including open-loop swimming control and typical closed-loop control strategies. In particular, we detail our latest studies on the RobCutt series underwater robots. On this basis, some critical issues and future directions are summarized. We predict that biomimetic underwater robots will have excellent prospects in underwater environment exploration and resource utilization.

The parental active model: A unifying stochastic description of self-propulsion.

Abstract: We propose a new overarching model for self-propelled particles that flexibly generates a full family of "descendants." The general dynamics introduced in this paper, which we denote as the "parental" active model (PAM), unifies two special cases commonly used to describe active matter, namely, active Brownian particles (ABPs) and active Ornstein-Uhlenbeck particles (AOUPs). We thereby document the existence of a deep and close stochastic relationship between them, resulting in the subtle balance between fluctuations in the magnitude and direction of the self-propulsion velocity. Besides illustrating the relation between these two common models, the PAM can generate additional offsprings, interpolating between ABP and AOUP dynamics, that could provide more suitable models for a large class of living and inanimate active matter systems, possessing characteristic distributions of their self-propulsion velocity. Our general model is evaluated in the presence of a harmonic external confinement. For this reference example, we present a two-state phase diagram that sheds light on the transition in the shape of the positional density distribution from a unimodal Gaussian for AOUPs to a Mexican-hat-like profile for ABPs.

MICROSCOPE satellite and its drag-free and attitude control system

Abstract: Abstract This paper focuses on the description of the design and performance of the MICROSCOPE satellite and its drag-free and attitude control system. The satellite is derived from CNES’ Myriade platform family, albeit with significant upgrades dictated by the unprecedented MICROSCOPE’s mission requirements. The 300 kg drag-free microsatellite has completed its 2 years flight with higher-than-expected performances. Its passive thermal concept allowed for temperature variations smaller than 1 μ K at the frequency of the equivalence principle test f EP . The propulsion system provided a six-axis continuous and very low noise thrust from zero to some hundreds of micronewtons. Finally, the performance of its DFACS (aimed at compensating the disturbing forces and torques applied to the satellite) is the finest ever achieved in low Earth orbit, with residual accelerations along the three axes lower than 10 −12 m s −2 at f EP over 8 days.

Driving Droplets on Liquid Repellent Surfaces via Light‐Driven Marangoni Propulsion

Abstract: Marangoni flow, a surface shear flow, is a promising option for propulsion when controlling liquid droplet motion on solid substrates. However, the applicability of Marangoni flow induced by heating the substrate for droplet manipulation is limited by low precision of motion control and a narrow range of substrate types. Herein, a novel noncontact light‐driven droplet manipulation method by using photothermally active droplets is introduced. Marangoni flow is induced by local photothermal heating via near‐infrared (NIR) irradiation resulting in an internal flow that drives the droplets. The photothermally active droplets slide away from the NIR light and the direction of motion can be precisely controlled by changing the irradiation position remotely. In addition, it is demonstrated that the addition of a miscible liquid to the droplets can reverse the direction of motion. Moreover, the authors show that spherical droplets on conventional liquid repellent surfaces move through a rolling mechanism instead of sliding. It is believed that this droplet manipulation method can provide a general way of droplet transportation on solid surfaces.

Overview of Propulsion Systems for Unmanned Aerial Vehicles

Abstract: Unmanned Aerial Vehicle (UAV) propulsion technology is significantly related to the flight performance of UAVs, which has become one of the most important development directions of aviation. It should be noted that UAVs have three types of propulsion systems, namely the fuel, hybrid fuel-electric, and pure electric, respectively. This paper presents and discusses the classification, working principles, characteristics, and critical technologies of these three types of propulsion systems. It is helpful to establish the development framework of the UAV propulsion system and provide the essential information on electric propulsion UAVs. Additionally, future technologies and development, including the high-power density motors, converters, power supplies, are discussed for the electric propulsion UAVs. In the near future, the electric propulsion system would be widely used in UAVs. The high-power density system would become the development trend of electric UAVs. Thus, this review article provides comprehensive views and multiple comparisons of propulsion systems for UAVs.

Gastrointestinal tract drug delivery using algae motors embedded in a degradable capsule

Abstract: The use of micromotors for active drug delivery via oral administration has recently gained considerable interest. However, efficient motor-assisted delivery into the gastrointestinal (GI) tract remains challenging, owing to the short propulsion lifetime of currently used micromotor platforms. Here, we report on an efficient algae-based motor platform, which takes advantage of the fast and long-lasting swimming behavior of natural microalgae in intestinal fluid to prolong local retention within the GI tract. Fluorescent dye or cell membrane-coated nanoparticle functionalized algae motors were further embedded inside a pH-sensitive capsule to enhance delivery to the small intestines. In vitro, the algae motors displayed a constant motion behavior in simulated intestinal fluid after 12 hours of continuous operation. When orally administered in vivo into mice, the algae motors substantially improved GI distribution of the dye payload compared with traditional magnesium-based micromotors, which are limited by short propulsion lifetimes, and they also enhanced retention of a model chemotherapeutic payload in the GI tract compared with a passive nanoparticle formulation. Overall, combining the efficient motion and extended lifetime of natural algae-based motors with the protective capabilities of oral capsules results in a promising micromotor platform capable of achieving greatly improved cargo delivery in GI tissue for practical biomedical applications.

Field-Induced Assembly and Propulsion of Colloids

Abstract: Electric and magnetic fields have enabled both technological applications and fundamental discoveries in the areas of bottom-up material synthesis, dynamic phase transitions, and biophysics of living matter. Electric and magnetic fields are versatile external sources of energy that power the assembly and self-propulsion of colloidal particles. In this Invited Feature Article, we classify the mechanisms by which external fields impact the structure and dynamics in colloidal dispersions and augment their nonequilibrium behavior. The paper is purposely intended to highlight the similarities between electrically and magnetically actuated phenomena, providing a brief treatment of the origin of the two fields to understand the intrinsic analogies and differences. We survey the progress made in the static and dynamic assembly of colloids and the self-propulsion of active particles. Recent reports of assembly-driven propulsion and propulsion-driven assembly have blurred the conceptual boundaries and suggest an evolution in the research of nonequilibrium colloidal materials. We highlight the emergence of colloids powered by external fields as model systems to understand living matter and provide a perspective on future challenges in the area of field-induced colloidal phenomena.

Intelligent Torque Allocation Based Coordinated Switching Strategy for Comfort Enhancement of Hybrid Electric Vehicles

Abstract: This paper proposes two intelligent torque distribution strategies based on particle swarm optimization (PSO) and fuzzy logic control (FLC) to provide convenient torque allocation that maximizes hybrid electric vehicle (HEV) propulsion power. PSO torque distribution strategy uses torque transfer ratio (TTR) as a fitness function to select the best torque candidates and differential arrangements that maximize HEV propulsion torque. A proposed FLC controller with adequate membership functions is designed to ensure convenient torque vectoring across vehicle wheels. New coordinated switching strategy is proposed in this paper to address the undesired transient ripples occurring during drivetrain commutations and power source switchings. The proposed coordinated switching strategy controls the switching period duration through transition functions fitting the transient dynamics of power sources. In non-uniform surfaces, intelligent torque allocation strategies converted 84~86% of the generated torque into propulsion torque whereas equal torque distribution strategy yielded a torque transfer ratio of 50%. Thanks to the proposed coordinated switching strategy, DC bus voltage ripples were reduced into a narrow band of ± 5V, transient power ripples were limited to a narrow band of 600 W and torque jerks were almost suppressed. Real-time simulation using the RT LAB platform confirms that the proposed coordinated switching strategy have reduced transient torque overshoot from 69% to almost zero and this is expected to improve HEV driving comfort.

Study on Applicability of Energy-Saving Devices to Hydrogen Fuel Cell-Powered Ships

Abstract: The decarbonisation of waterborne transport is arguably the biggest challenge faced by the maritime industry presently. By 2050, the International Maritime Organization (IMO) aims to reduce greenhouse gas emissions from the shipping industry by 50% compared to 2008, with a vision to phase out fossil fuels by the end of the century as a matter of urgency. To meet such targets, action must be taken immediately to address the barriers to adopt the various clean shipping options currently at different technological maturity levels. Green hydrogen as an alternative fuel presents an attractive solution to meet future targets from international bodies and is seen as a viable contributor within a future clean shipping vision. The cost of hydrogen fuel—in the short-term at least—is higher compared to conventional fuel; therefore, energy-saving devices (ESDs) for ships are more important than ever, as implementation of rules and regulations restrict the use of fossil fuels while promoting zero-emission technology. However, existing and emerging ESDs in standalone/combination for traditional fossil fuel driven vessels have not been researched to assess their compatibility for hydrogen-powered ships, which present new challenges and considerations within their design and operation. Therefore, this review aims to bridge that gap by firstly identifying the new challenges that a hydrogen-powered propulsion system brings forth and then reviewing the quantitative energy saving capability and qualitive additional benefits of individual existing and emerging ESDs in standalone and combination, with recommendations for the most applicable ESD combinations with hydrogen-powered waterborne transport presented to maximise energy saving and minimise the negative impact on the propulsion system components. In summary, the most compatible combination ESDs for hydrogen will depend largely on factors such as vessel types, routes, propulsion, operation, etc. However, the mitigation of load fluctuations commonly encountered during a vessels operation was viewed to be a primary area of interest as it can have a negative impact on hydrogen propulsion system components such as the fuel cell; therefore, the ESD combination that can maximise energy savings as well as minimise the fluctuating loads experienced would be viewed as the most compatible with hydrogen-powered waterborne transport.