Propulsion - Science topic

Unconventional system that are generally adopted for ship propulsion are Ducted Propellers. These devices have recently been studied with medium-fidelity computational fluid dynamics code (based on the potential flow hypothesis) with promising results. Numerical and experimental comparison of ducted propeller with PBCF, case studies with Propeller...

High-energy-density fuels play a vital role in the development of the aviation industry because they can provide more propulsion energy than conventional liquid fuels. Constructing more five-or six-membered rings in fuel molecules is an efficient way to increase fuel density. However, as the number of rings increases, the hydrogen content of fuel m...

The Energy Efficiency Design Index (EEDI) was adopted by the International Maritime Organization (IMO) with the aim of reducing CO2 emissions from shipping. As this is a mandatory measure for all seagoing ships over 400 Gross Tonne which is becoming stringent over time, the need for economic and alternative propulsion has become more important than...

The scale of volcanic eruptions influences the effects of wide-ranging disasters involving ashfall, such as the disruption of lifelines and paralysis of urban functions. This highlights the importance of vehicle availability on ash-covered roads for disaster management personnel involved in rescue and recovery efforts and for citizens who must evac...

Biological and artificial microswimmers often have to propel through a variety of environments, ranging from heterogeneous suspending media to strong geometrical confinement. Under confinement , local flow fields generated by microswimmers, and steric and hydrodynamic interactions with their environment determine the locomotion. We propose a squirm...

This paper analyzes the possibility of maintaining a circular displaced non-Keplerian orbit around the Sun by means of a Sun-facing diffractive sail. With the goal of monitoring the Earth’s high-latitude regions, the spacecraft is required to track its displaced orbit at an angular velocity equal to the mean motion of the planet. In doing so, the s...

The study was carried out on a model of a small-sized aircraft of the type of a flying wing, which has a V-shape in plan. The structure of the flow on the wing surface was studied depending on the angle of attack and deflection of the controls. Experiments were carried out to study the influence of the work of the distributed electric propulsion on...

This article was declared to the Office of inventions in Morocco (OMPIC) and published under License CC BY-NC after filing the patents of the two related inventions. Abstract : Airplanes are nowadays the main transport solution for travelers and this makes aviation one of the most important and strategic social and economic fields. However, tragedi...

The article presents the results of experimental studies on the influence of the work of a distributed electric propulsion on the flow around the straight wing of a small-sized aircraft. The flow structure was studied at natural (flight) Reynolds numbers, taking into account the angle of attack. The results of the experiments are visualization patt...

Multiphase pumps operate under different flow conditions with different work performance. In order to reveal the energy conversion regulations in multiphase pumps under different flows, this paper presents an analysis of the effects of different flows on the pressure propulsion power, Lamb vector dispersion, and vortex enstrophy dissipation in the...

The propulsion and acceleration of nanoparticles with light have both fundamental and applied significance across many disciplines. Needle‐free injection of biomedical nano cargoes into living tissues is among the examples. Here a new physical mechanism of laser‐induced particle acceleration is explored, based on abnormal optothermal expansion of m...

Project Lyra is all about realising a mission to 'Oumuamua. In this study I have investigated the use of NTP for achieving this goal.

A study is performed to comprehensively evaluate the aerodynamic performance of a regional aircraft designed for short-haul flights, with a particular focus on the effects of distributed electric propulsion (DEP) on aerodynamic performances. This effort aligns well with a core objective of the Clean Aviation program to decrease carbon emissions wit...

The global shipping sector requires deep and rapid carbon reductions within a decade to align with Paris Agreement goals. Wind propulsion offers a retrofit option where sails provide renewable power to reduce emissions from a ship's engine. Combining wind propulsion with voyage optimisation shows synergistic potential, but the underlying technical...

The adoption of hybrid–electric propulsion, allowing us to partially replace fuel with batteries and to reduce aircraft in-flight emissions, represents one of the main investigated solutions to mitigate the aviation climate impact. Despite its environmental potential being appealing for a practical application, two main drawbacks limit the actual i...

The influence of electromagnetic fields on human organisms is currently a popular direction of research in numerous research centers around the world. The article deals with the measurement of the radiated component of the electromagnetic field, which accompanies the operation of the still popular universal commutator motors and the passive method...

A major challenge in the study of active systems is to harness their non-equilibrium dynamics into useful work. We address this by showing how to design colloids with controllable spontaneous propulsion or rotation when immersed in active nematics. This is illustrated for discs with tilted anchoring and chiral cogs, for which we determine the nemat...

The study employs a risk-based approach for ship propulsion system retrofitting analysis to reduce CO 2 emissions and enhancing cost efficiency. The analysis is based on historical data from the EU-MRV database collected for ships operating in the Black Sea using the Carbon Intensity Indicator (CII). Based on the Attained CII/Required CII rate, fou...

Composite booms for solar sails have been prototyped by using innovative smart materials. Shape memory polymer composites (SMPCs) have been manufactured by interposing SMP layers between carbon-fiber-reinforced (CFR) plies. A polyimide membrane has been embedded into the CFR-SMPC frame of the sail during lamination. The sail’s size has been limited...

Motile bacteria play essential roles in biology that rely on their dynamic behaviours, including their ability to navigate, interact and self-organize. However, bacteria dynamics on fluid interfaces are not well understood. Swimmers adsorbed on fluid interfaces remain highly motile, and fluid interfaces are highly non-ideal domains that alter swimm...

Unsteady inlet flow distortion can influence the stability and performance of any propulsion system, in particular for more novel, short and slim intakes of future aero-engine configurations. The requirement for measurement methods able to provide high spatial resolution data is important to aid the understanding of these flow fields. This work pre...

This paper explores the role of the computational fluid dynamics (CFD) modeling technique in the aerodynamic design and propulsion system of the formula 1 car. It provides a study of Reynolds number influences on the state of the boundary layer, unstable and steady flow, time-dependent wake structure, interacting shear layer and separate flows thro...

Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation. Metal-based degradable micromotor composed of magnesium (Mg), zinc (Zn), and iron (Fe) have promise due to their nontoxic fuel-free propulsion, favorable biocompatibility, and safe excretion of degradation products Recent advances in degradable metal...

This study aimed to quantify and analyze the acceleration and rotation of the upper limb during three fundamental techniques in table tennis. The chosen instrument is the inertial sensor K-TRACK, (K-Sport Montelabbate, Italy) equipped with 3D sensors capable of reading up to 4000 Hz (operating at 200 Hz). The experimental group for this research co...

As humans continue to explore the aerospace field, higher demands have been placed on new types of propulsion systems. Meanwhile, active secondary flow has been applied to various aspects of engines over the past seventy years, significantly enhancing engine performance. For the new generation of propulsion systems, active secondary flow remains a...

Aerospace materials play a crucial role in modern aerospace technology. This paper is mainly a comprehensive overview of aerospace materials, including their classification, properties and applications. Aerospace materials are used in a wide range of applications, including aircraft and spacecraft, propulsion systems, and electronics. The paper als...

The implementation of tax reduction policies in China represents a significant and effective strategy. Accordingly, this strategy has been designed to facilitate the development of a green economy by establishing a market-oriented allocation system for environmental and resource elements, while simultaneously invigorating microeconomic entities. As...

In this study, we present a multilayer DC-DC converter design that was inspired by biology for the purpose of speeding the charging of plug-in hybrid vehicles and electric vehicles (EVs and PHEVs). The unregulated power from the front-end ac-dc converter is sent to the dc-dc converter's specified bioinspired design, where it is then utilised by the...

The aim of this study is to investigate and optimize the dynamic properties of an entire structural unit. Using modal analysis and experimental measurements of the propulsion system, natural frequencies with close agreement were identified. The drive was able to work within the frequency range during start-up and normal operation, but due to variou...

Dynamically manipulating droplet motion on hydrophobic surfaces is crucial in various fields, including biomedical, sensing, actuation, and oil–water separation applications. Ferrofluid droplets can be manipulated and controlled using external magnetic forces. The creation of ferrofluids involves multiple procedures that can affect the functionalit...

This research paper presents a data-based energy management method for a vessel that predicts the upcoming load demands based on data from weather information and its automated tracking system. The vessel is powered by a hybrid propulsion system consisting of a high-temperature fuel cell system to cover the base load and a battery system to compens...

Currently, smart technologies are rapidly gaining popularity in various industries, including the maritime sector [...]

The aim of this paper is to analyze the performance of a state-feedback guidance law, which is obtained through a classical sliding mode control approach, in a two-dimensional circle-to-circle orbit transfer of a spacecraft equipped with a continuous-thrust propulsion system. The paper shows that such an inherently robust control technique can be e...

Environmental issues have reached global attention from both political and social perspectives. Many countries and companies around the world are adopting measures to help change current trends. Awareness of decarbonization in the transportation sector has led to an increasing development of energy storage systems in recent years, especially for gr...

There is a need to minimise the Greenhouse Gas Emissions (GHG) of petrol-powered cars during the transition to net zero. This research examines the effects on GHG from the recent adoption of E10 as the standard 95-octane petrol grade in the United Kingdom (UK). Also, it considers the potential of using higher bioethanol blends within the national c...

Abstract: Gas turbine engines are widely used in various industries such as aviation, power generation, and marine propulsion due to their high efficiency and reliability. The combustion chamber of a gas turbine engine design contains a number of elements, including as the chamberʹs size and form, the fuel injection system, the ignition system, and...

¿Cuándo se debilita o entra en contradicción un régimen u orden internacional?¿Por qué se dice que el orden nuclear internacional actual está en crisis? Este artículo trata de abordar posibles respuestas a estas preguntas para contribuir al debate en torno al aparente debilitamiento del Régimen Internacional de No Proliferación. Para ello analiza d...

The current paper is focused on the conceptual design of a thermal management system with a liquid working medium for a commuter hybrid-electric aircraft, featuring a series propulsion configuration. Regarding the system’s architecture, parametric analyses are conducted, by altering the number of heat exchangers. To clarify, a centralised and a dec...

La propulsion par champ d’accélération permet d’accéder à une manœuvrabilité et des accélérations de loin supérieures à celles accessibles avec la propulsion par la poussée. Le champ gravitationnel terrestre est un bon exemple de champ d’accélération. D’une grandeur et d’une direction à peu près constante sur la surface du globe, ce champ est sans...

¿Cuándo se debilita o entra en contradicción un régimen u orden internacional? ¿Por qué se dice que el orden nuclear internacional actual está en crisis? Este artículo trata de abordar posibles respuestas a estas preguntas para contribuir al debate en torno al aparente debilitamiento del Régimen Internacional de No Proliferación. Para ello analiza...

This paper investigates the suitability of sun-synchronous orbits (SSOs) as an injection location for responsive maneuverable spacecraft. This work identifies a range of near circular, repeating ground track (RGT) orbits that can be easily maneuvered into from SSOs. Four orbits that are simultaneously sun-synchronous and have a RGT are found, which...

Given the increase in air traffic, the main challenges in aircraft design are in-flight emissions and noise heard by the community. These problems have thus far been solved by incremental improvements in aerodynamics, engine technology and operation. To dramatically reduce aviation’s carbon footprint towards an environmentally friendly air transpor...

Is there a gap in the Nuclear Weapons Nonproliferation Regime related to nuclear material for the propulsion of submarines by Non-nuclear Weapons States? This question arises with the steady advancement of the Brazilian nuclear-powered submarine program and within the AUKUS strategic partnership. This article argues that there is no such gap since...

The automotive industry is involved in a massive transformation from standard endothermic engines to electric propulsion. The core element of the Electic Vehicle (EV) is the battery pack. Battery pack production misses regulations concerning manufacturing standards and safety-related issues. In such a fragmented scenario, the increasing number of E...

The Free Piston Engine (FPE) coupled to the Linear Electric Machine (LEM) can be considered a viable low-carbon thermal propulsion technology. However, being dynamically constrained by its translational coupled loads impedes its operational stability and has been challenging to solve for academia and industry. This paper addresses this critical c...

The linear induction motor based on local public transport has turned out to be more cost-effective in respect of energy cost as well as maintenance. This is due to the fact that linear induction motors constitute a strong durability rate, simple geometrical structure, large force application capability, and independent adhesiveness that make the m...

This research deals with electromagnetic compatibility (EMC) in the field of electric propulsion (EP). To complete previous investigations, the emissions of a fully operating radio-frequency thruster (RIT)-including its extracted ion beam-were numerically analyzed. The ion beam was simulated and investigated with various characteristics. The simula...

The use of Hydrogen-powered propulsion in railways is very promising and already found relevant commercial applications. Some potential barriers emerged anyway as critical issues addressed by the scientific community , about the Hydrogen distribution and storage onboard. Indeed, Hydrogen Refueling Stations (HRS) and tankers must fulfill safety crit...

Energy storage systems (ESSs) are critically important for the future of electric vehicles. Due to the shifting global environment for electrical distribution and consumption, energy storage systems (ESS) are amongst the electrical power system solutions with the fastest growing market share. Any ESS must have the capacity to regulate the modules f...

The integration of microorganisms and engineered artificial components has shown considerable promise for creating biohybrid microrobots. The unique features of microalgae make them attractive candidates as natural actuation materials for the design of biohybrid microrobotic systems. In this review, w e will introduce microalgae‐based biohybrid mic...

A fully kinetic axisymmetric particle-in-cell model is employed to simulate and study the detachment processes of electrons in the propulsive magnetic nozzle. The detachment rate is adopted to evaluate the extent to which the electrons detach from the magnetic field. The theoretical expression for the electron detachment rate is derived and indicat...

Background: Although significant progress has been made in treatment techniques for renal and ureteral calculi, residual fragments (RF) persisting long after treatment pose a serious threat to patients’ health. A variety of novel physical techniques and extraction devices are currently being developed to promote the removal of RF from the urinary s...

Air-breathing electric propulsion (ABEP) refers to a spacecraft in very-low Earth orbit (VLEO) harnessing upper atmospheric air as propellant for an electric thruster. This allows the orbital altitude to be maintained via drag-compensation, removing the need for on-board propellant storage and allowing a mission lifetime which is not limited by pro...

Nanowire array targets exhibit high optical absorption when interacting with short, intense laser pulses. This leads to an increased yield in the production of accelerated particles for a variety of applications. However, these interactions are sensitive to the laser prepulse and could be significantly affected. Here, we show that an array of align...

The hybrid electric vehicle combines dual propulsion systems: one employs the traditional internal combustion engine, while the other utilizes a PMDC or BLDC motor. Generally, BLDC motors exhibit an efficiency of 85% to 90%. Conversely, the PMDC motor inherently achieves an efficiency of 88% under optimal running conditions. Moreover, improving the...

Our aim was to investigate if using a warm-up routine that included parachute-resisted sprints with large hand-paddles improves 50 m freestyle performance in trained collegiate swimmers. Twelve swimmers (23.9 ± 2.2 years, 179 ± 7 cm, 77.1 ± 10.6 kg) participated in the study and completed two 50-m freestyle races, each preceded by a different warm-...

The Hyperloop, often referred to as the future of transportation, is an innovative mode of ultra-high-speed rail transportation that promises to revolutionize the way people and goods are moved. This review paper aims to provide a comprehensive overview of the Hyperloop transportation system, covering its conceptualization, design, technical aspect...

L’invenzione qui riassunta concerne una navicella spaziale a doppio toroidale con funzione di acceleratore di particelle o LHC, connesso ognuno al proprio motore a ioni installato al centro di ogni stesso LHC, ma in modo verticale rispetto alla direzione di marcia della navicella in quanto, gli stessi detti motori ionici, in questo caso, non verran...

Rotating detonation engines (RDEs) are considered to be promising thrusters for aerospace propulsion. Detonation initiation in RDEs can be accompanied by a destructive explosion of an excess volume of the fuel mixture in the combustor. To exclude this phenomenon, a “mild” rather than “strong” initiation of detonation is required. For the mild initi...

São apresentadas contribuições técnicas para a otimização do projeto de sistemas de propulsão e de manobras de embarcações fluviais. A partir de análises dos requisitos operacionais de embarcações fluviais, buscando sempre equilibrar alta eficiência com segurança da navegação e com baixa interferência ambiental, foram analisados itens importantes d...

Open-sea testing of a two-phase marine ramjet vehicle has been conducted. This experimental phase was accomplished following comprehensive theoretical research. The concept of two-phase marine ramjet propulsion consists of a submerged propulsor acquiring water through an inlet due to the vehicle’s motion. Thrust is generated by injecting and disper...

The trend in the development of maritime and river propulsion systems is to make a transition from hydrocarbon to more environmentally friendly solutions. This contributes positively to the solution of the problems identified by the International Maritime Organization (IMO) regarding the high emissions of polluting gases emitted by maritime transpo...

The running biomechanics of running shoes have been extensively investigated. However, there is limited knowledge about the use of bionic shoes compared to neutral shoes, along with the velocities involved in their use. The aim of this study was to examine the biomechanical alterations associated with various running velocities of bionic shoes. By...

Neste trabalho realiza-se o dimensionamento e a análise da resistência mecânica com utilização de métodos analíticos e numéricos, para a construção da estrutura de um protótipo de Eco-táxi ciclístico. A pesquisa é multidisciplinar, envolvendo o uso de recursos computacionais aplicados ao projeto. Tal desenvolvimento visa contribuir com a inovação t...

This paper explores the role of the computational fluid dynamics (CFD) modeling technique in the aerodynamic design and propulsion system of the formula 1 car. It provides a study of Reynolds number influences on the state of the boundary layer, unstable and steady flow, time-dependent wake structure, interacting shear layer and separate flows thro...

Topological photonic crystals, which offer topologically protected and back-scattering-immune transport channels, have recently gained significant attention for both scientific and practical reasons. Although most current studies focus on dielectric materials with weak dispersions, this study focuses on topological phases in dispersive materials an...

The implementation of distributed propulsion and boundary layer ingestion for unmanned aerial vehicles represents various challenges for the design of embedded ducts in blended wing body configurations. This work explores the conceptual design and evaluation of DP configurations with BLI. The aerodynamic integration of each configuration is evaluat...

Study aim : This study aimed to compare gait biomechanical data on the unaffected side before and six months after total knee arthroplasty (TKA) and determine the postoperative changes in medial knee loading on the unaffected side. Material and methods : Three-dimensional gait analysis was performed on 19 female patients who had underwent TKA. Gait...

The propulsion for mammalian sperm swimming is generated by flagella beating. Microtubule doublets (DMTs) along with microtubule inner proteins (MIPs) are essential structural blocks of flagella. However, the intricate molecular architecture of intact sperm DMT remains elusive. Here, by in situ cryo-electron tomography, we solved the in-cell struct...

Maximal sprinting in humans requires the contribution of various muscle–tendon units (MTUs) and joints to maximize performance. The plantar flexor MTU and ankle joint are of particular importance due to their role in applying force to the ground. This narrative review examines the contribution of the ankle joint and plantar flexor MTUs across the p...

This research paper focuses on the vital role of Brushless Direct Current (BLDC) motors in hybrid vehicle propulsion due to their efficiency and compact design. The primary objective is to evaluate BLDC motor performance within a vehicle chassis, with a specific focus on vibration characteristics. An innovative rotational tracker program is introdu...

As the aviation industry seeks sustainable propulsion solutions, innovative technologies have emerged, among which rim-driven fan (RDF) systems hold notable promise. This comprehensive review paper deeply investigates RDF technology, uncovering its principles, benefits, and transformative potential for aviation propulsion. Amid escalating concerns...

In recent years, with the development of ship electric propulsion system, High Temperature Superconducting (HTS) motors have gained attention as a promising potential resolution due to their high-power density and the progression of cryogenic refrigeration technology. We present an electromagnetic characteristics numerical analysis of 40 MW, 120 rp...

The attenuation of sensory inputs via various methods has been demonstrated to impair balance control and alter locomotor behavior during human walking; however, the effects of attenuating foot sole sensation under distinct areas of the foot sole on lower extremity motor output remains poorly understood. Thus, the purpose of this study was to atten...

Background The tethered swimming (TS) is an ergometer where swimming is simulated in an ecological environment, commonly used for assessing force in water. Objective This systematic review aims at a critical appraise of the literature on the biomechanical and physiological variables obtained from many protocols and tests assessing force–time curve...

The automotive industry constitutes a long-established and significant sector of the world economy. Indeed, experts in international economic relations recognise that the automotive sector is highly concentrated, involves significant international investment and links different industries. Car trade represents an important part of international...