Propulsion Model Research Articles

Full scale KCS self-propulsion simulation using different propulsion models

It is critical to be able to estimate the full-scale ship self-propulsion, since the more real sailing performance of the ship can be assessed. Results of scaling model are used to predict full-scale self-propulsion performance. However, the difference between the full-scale prediction and reality would be caused by scale effect. URANS simulations is conducted to predict self-propulsion of a full-scale KRISO Container Ship with the propeller KP505. Design speed is selected as simulation working condition according to Gothenburg 2010. In house CFD code HUST-Ship will be used to solve RANS equation coupled with two degrees of freedom (2DOF) solid body motion equations including heave and pitch. RANS equations are discretized by finite difference method and solved by PISO algorithm. The discretized propeller model and improved body-force model are used as the propulsion models. Grid and time step sensitivity analysis of full-scale propeller and hull is conducted separately. The self-propulsion indexes of full-scale simulation are compared with the extrapolation of model experimental data and full-scale simulation results from literatures. The prediction self-propulsion indexes based on different propulsion models are compared and discussed.

Numerical Simulation of Radiative MHD Sutterby Nanofluid Flow Through Porous Medium in the Presence of Hall Currents and Electroosmosis

Analysis of thermal and fluid phenomena based on the fluid dynamics theory leads to understanding of fundamental mechanisms in modern technologies. Thermal/fluid transport is critical to many applications, such as photothermal cancer therapy, solar thermal evaporation and polymer composites. The current study focusses to investigate the effect of magnetohydrodynamics, Hall currents and electroosmosis on the propulsion of Sutterby nanofluids in a porous microchannel. The Brownian motion and thermophoresis effects have also been considered. The governing equations for the momentum, temperature and nanoparticle volume fraction have been modified under the suitable non-dimensional quantities. The resulting dimensionless system of equations have been solved using bvp4c package in computational software MATLAB. The pictorial representations have been presented for various flow quantities with respect to sundry fluid parameters. It is noted from the investigation that, there is a decrease in fluid velocity with an increase in Hartmann number, temperature decreases with the increment in radiation parameter and nanoparticle volume fraction reduces with the increment of Prandtl number and thermophoresis parameter. The results obtained for the Sutterby nanofluid propulsion model reveal many engrossing behaviors and has many applications such as disease diagnostics and cancerous tissues destruction, and that provide a further dimension to investigate the nanofluid flow problems with thermophysical properties in two/three dimensions.

Modeling of a Marine Hydrokinetic Cycloturbine Vehicle

A marine hydrokinetic (MHK) cycloturbine is a renewable electric power generation system used in rivers or tidal environments to address the need for electricity in remote regions. MHK cycloturbines have hydrofoils oriented perpendicular to the flow in a paddlewheel configuration, and use lift generated from these foils to produce power. Due to the high cost associated with its operation and maintenance, an MHK system with four stacked counter-rotating turbines that can self-deploy and with propulsion and control mechanisms similar to a cycloturbine aircraft has been designed. A detailed turbine simulation model is necessary to understand the vehicle dynamics and assist in the design of the vehicle controllers. The simulation model solves the six degree-of-freedom rigid body equations of motion for the maneuvering MHK system subject to the hydrodynamic lift and drag forces, hydrostatic forces, and the propulsive forces from the turbines. The turbine propulsive force model is matched to computational fluid dynamics analysis and experimental data. Experimental work includes investigation at 1/5.56 scale of a single turbine rapid prototype device and a subscale demonstrator in a reverberant tank.

Data-driven modelling of ship propulsion and the effect of data pre-processing on the prediction of ship fuel consumption and speed loss

Data-driven models for ship propulsion are presented while the effect of data pre-processing techniques is extensively examined. In this study, a large, automatically collected with high sampling frequency data set is exploited for training models that estimate the required shaft power or main engine fuel consumption of a container ship sailing under arbitrary conditions. Emphasis is given to the statistical evaluation and pre-processing of the data and two algorithms are presented for this scope. Additionally, state-of-the-art techniques for training and optimizing Feed-Forward Neural Networks (FNNs) are applied. The results indicate that with a delicate filtering and preparation stage it is possible to significantly increase the model's accuracy. Therefore, increase the prediction ability and awareness regarding the ship's hull and propeller actual condition. Furthermore, such models could be employed in studies targeting at the improvement of ship's operational energy efficiency.

CLASSIFICAÇÃO E DESCRIÇÃO TÉCNICA DAS EMBARCAÇÕES PESQUEIRAS ATUANTES EM SANTARÉM, ESTADO DO PARÁ

This study aimed to characterize fishing boats in the municipality of Santarém. The data were collected through interviews carried out from January 2017 to December 2018, in places where the fishing fleet was busy and at various points the edge of the city. During this period, 150 semi-structured forms were applied mainly to the owners or agents of fishing boats and fishermen who landed fish, as well as the monitoring of landings and direct observations. The fishing boats in activity in the municipality and registered in the present study had dimensions varying from 3 to 20 meters in length, all units of the fishing fleet had the construction and structure in wood evidencing an artisanal production system. The fishing fleet was classified into seven categories: “cascos”, canoes, motorized canoes, “sapiaras”, “rabetão”, “bajaras” and “geleiras”, which differ in size, model and type of propulsion. The most frequent boats in the ports of Santarém were the group of canoes, in descending order of contribution, are the “rabetas”, canoes, “cascos”, “rabetão” and “sapiaras”, followed by the glaciers and “bajaras” boats. The physical conditions of the floodplain environment, with numerous canals, “paranás” and lakes that suffer fluctuations of the water level are determinant factors for the size of the boats justifying the great use of the hooves and canoes actually operating in the regional fishing activity, associated with a variation of fishing techniques that demand a differentiated means of transport. Therefore, this study proves that the fishing sector plays an important role in the regional economy, besides supplying the Santarém city.

Vibration analysis of ship propulsion shafting bearings

The ship power propulsion system is the "heart" of the ship, and the ship propulsion shafting is the core unit of the ship power propulsion system, and it is an indispensable part of the ship's propulsion torque and thrust transmission. The operating status of the propulsion shafting directly affects the operating conditions of the ship, and even the life of the ship. Bearing load is one of the most important manifestations of the operating state of the propulsion shafting. Focusing on changes in the bearing load can better study the operating state of the propulsion shafting. The research on the steady-state load of ship propulsion shafting meets the needs of ship development and has great value for practical engineering applications. This paper takes the ship propulsion shafting-oil film-bearing structure system as the research object. Through the steady-state load mathematical model of ship propulsion shafting bearings, it reveals the coupling relationship among ship propulsion shafting bearing load, oil film force, and journal position, and establishes the ship The steady-state load calculation method of the propulsion shafting bearings solves the basic theoretical problems of modeling and analysis of the steady-state operating state of the ship's propulsion shafting, and provides theoretical support for the safety prediction, management and evaluation of the ship's propulsion shafting operation.

Hybrid electric distributed propulsion overall aircraft design process and models for general aviation (FAST GA)

In the frame of the European objectives in terms of CO2 emissions, the aeronautics is looking for a technological rupture to achieve them, in particular, the aircraft design domain pursuits this through the research of innovative architectures. One of these innovative configurations currently being explored includes the hybrid electric energy source (thermal/electric) for Distributed Electric Propulsion (DEP) architecture. This Paper details a code developed to size a general aviation aircraft at concept level, by only defining its top level requirements and the main architecture parameters. The code can manage both conventional and hybrid power source as well as concentred or distributed propulsion architectures in order to allow the user to evaluate and compare the feasibility and benefits respectively of these innovative architectures. This code is a branch of the code “FAST-CS25” (Future Aircraft Sizing Tool for conventional CS-25 type) held by ONERA/ISAE-SUPAERO. The presented work aims at the expansion of the FAST code to CS-23 conventional type, hybrid electric energy source, and distributed propulsion system configurations. Through this paper, the models and the main sizing loops for the concept design are described, but putting special emphasis on the distributed propulsion aerodynamics and wing mass estimation. These detailed models where validated with the NASA X-57 DEP aircraft satisfactory. The whole concept design loop of a hybrid energy aircraft was validated with the eGenius hybrid energy aircraft.

ИСПОЛЬЗОВАНИЕ В ИЗОЛЯЦИОННЫХ ЭКСПЕРИМЕНТАХ ТЕХНОЛОГИЙ ВИРТУАЛЬНОЙ И ДОПОЛНЕННОЙ РЕАЛЬНОСТЕЙ ДЛЯ МОДЕЛИРОВАНИЯ ВЫХОДОВ В ОТКРЫТЫЙ КОСМОС БЕЗ СТРАХОВОЧНОГО ФАЛА

Analysis of realistic prototypes of a propulsive survival backpack (PSB) and current human-PSB models gave impetus to the development of original tools for designing the scenery and PSB application scenarios with consideration of the VR and 3D experiences in isolation studies and operators' training. Specifically, the authors created several VR/AR scenarios of emergency egress for participants in isolation studies.

In Vivo Biomechanical Assessment of a Novel Handle-Based Wheelchair Drive.

Push-rim wheelchair propulsion frequently causes severe upper limb injuries in people relying on the wheelchair for ambulation. To address this problem, we developed a novel handle-based wheelchair propulsion method that follows a cyclic motion within ergonomic joint ranges of motion. The aim of this study was to measure hand propulsion forces, joint excursions and net joint torques for this novel propulsion device and to compare its performance against traditional push-rim wheelchair propulsion. We hypothesized that under similar conditions, joint excursions of this novel handle-based device will remain within their ergonomic range and that the effectiveness of the propulsion forces will be higher, leading to lower average propulsion forces compared to push-rim propulsion and reducing the risk of injury. Eight paraplegic subjects propelled the new device at two different loads on a custom-made wheelchair-based test rig. Video motion capture and force sensors were used to monitor shoulder and wrist joint kinematics and kinetics. Shoulder and wrist loads were calculated using a modified upper-extremity Wheelchair Propulsion Model available in OpenSim. The results show that with this novel propulsion device joint excursions are within their recommended ergonomic ranges, resulting in a reduced range of motion of up to 30% at the shoulder and up to 80% at the wrist, while average resultant peak forces were reduced by up to 20% compared to push-rim propulsion. Furthermore, the lower net torques at both the shoulder and wrist demonstrate the potential of this novel propulsion system to reduce the risk of upper-extremity injuries.

Propulsive model of school safety for disaster in community school ～ Case report of Kita-Tsunashima Elementary School in Yokohama city ～

Propulsive model of school safety for disaster in community school ～ Case report of Kita-Tsunashima Elementary School in Yokohama city ～

Joint Optimization of Trajectory, Propulsion, and Thrust Powers for Covert UAV-on-UAV Video Tracking and Surveillance

Autonomous tracking of suspicious unmanned aerial vehicles (UAVs) by legitimate monitoring UAVs (or monitors) can be crucial to public safety and security. It is non-trivial to optimize the trajectory of a monitor while conceiving its monitoring intention, due to typically non-convex propulsion and thrust power functions. This article presents a novel framework to jointly optimize the propulsion and thrust powers, as well as the 3D trajectory of a solar-powered monitor which conducts covert, video-based, UAV-on-UAV tracking and surveillance. A multi-objective problem is formulated to minimize the energy consumption of the monitor and maximize a weighted sum of distance keeping and altitude changing, which measures the disguising of the monitor. Based on the practical power models of the UAV propulsion, thrust and hovering, and the model of the harvested solar power, the problem is non-convex and intangible for existing solvers. We convexify the propulsion power by variable substitution, and linearize the solar power. With successive convex approximation, the resultant problem is then transformed with tightened constraints and efficiently solved by the proximal difference-of-convex algorithm with extrapolation in polynomial time. The proposed scheme can be also applied online. Extensive simulations corroborate the merits of the scheme, as compared to baseline schemes with partial or no disguising.

Real time Energy Efficiency Operational Indicator: Simulation research from the perspective of life cycle assessment

CO2 emissions during ship building, maintenance, and scrapping are not be involved when defining Energy Efficiency Operational Indicator (EEOI). However, these CO2 emissions can only show its value during operation phase of ship life. In order to evaluate the effect of CO2 emissions during ship building, maintenance, and scrapping on energy efficiency, a real time EEOI definition was put forward, a life cycle assessment (LCA) calculation framework was established, and a ship propulsion model with main diesel engine was built. A bulker carrier YUMING was taken as the case ship. CO2 emissions during ship building, maintenance, and scrapping were calculated. Main engine revolution and real time EEOI value with other parameters were obtained by simulating in different ship draft. The results show that life cycle assessment result will explicitly increase the real time EEOI value especially in lower engine speed and lower ship draft. The engine revolution at the lowest EEOI value will increase explicitly by life cycle assessment result. It means that the lower limit of ship speed should increase during slow steaming. Therefore, slow steaming may bring less environmental benefit if the life cycle assessment result is involved.

Estimation of adequacy of the simulation model of a water-jet propulsion drive of high-speed tracked amphibious vehicles

There is a research study of the dynamic properties of water jet drives designed both for different high-speed tracked amphibious vehicles types and for various loads. It is within the framework of the problem solving of dynamic loading decrease of high-speed tracked amphibious vehicles water jet drives. To achieve this goal, a mathematical model was synthesized and a simulation model was developed. During experimental studies the validity check of simulation mathematical model of high-speed tracked amphibious vehicles water jet drive operation was carried out. In this regard, various operating modes in specific transients were taken into account.

ANALISA PERFORMA KAPAL KM. CIREMAI DENGAN MODIFIKASI PENAMBAHAN PROPELLER HUB CAPS FIN DENGAN METODE EKSPERIMEN

The various ship propulsion models there are several considerations in the selection to be applied to the ship, such considerations are required in the planning of the ship's propulsion. With the addition of propeller hub caps fin is expected to deliver a flow model that supports the performance of propulsion systems on ship. The purpose to analyzes the best performance of the propeller shaft engine, representing a comparison of fuel consumption efficiency, as well as ship speed based on the addition of propeller hub caps fin on MV. CEREMAI. Method used was conducted experimentally to determine the performance of the ship's engines before and after using energo pro fin (propeller hub caps fin) with sea trial. Result shows 2% reduction in fuel consumption on the portside main engine and 3% starboard main engine. As well as enabling increased operational speed of KM ships. CIREMAI at 12% with the same rpm round. So selection of ship propeller types affects the performance of enegro profin (propeller hub caps fin).

Real Time Energy Efficiency Operational Indicator (EEOI): Simulation Research from the Perspective of Life Cycle Assessment

In order to evaluate the effect of CO2 emissions during ship building, maintenance and scrapping on energy efficiency, a real time EEOI definition was put forward, a life cycle assessment calculation framework was established, and a ship propulsion model with main diesel engine was built. A bulker carrier YUMING was taken as the case ship. CO2 emissions during ship building, maintenance, and scrapping were calculated. Main engine revolution and real time EEOI value with other parameters were obtained by simulating in different ship draft. The results show that life cycle assessment result will explicitly increase the real time EEOI value especially in lower engine speed and lower ship draft. It means that slow steaming may bring less environmental benefit if the life cycle assessment result is involved.

Modeling and analysis of performance and emissions of marine lean-burn natural gas engine propulsion in waves

In many vessels, the prime mover is a diesel engine, while the researchers recommended using natural gas as an attractive option to comply with the latest emission legislations. This study aims to analyze the dynamic response of a spark-ignition engine fueled by natural gas. Due to the complexity of power system operation in transient conditions, ship propulsion modeling is performed to assess the environmental impact of dynamic load. A co-simulation modeling in MATLAB- SIMULINK platform was developed to couple the medium-speed, four-stroke, turbocharged, spark-ignition engine to a propeller immersed in seawater. The engine’s essential elements were implemented, and the validity of the modeling was evaluated using the manufacturer’s data in both steady-state and transient conditions. The main goal was to determine the importance of the transient loads on the engine response, particularly during harsh weather conditions. Hence, simulations of various wave conditions with multiple wave amplitude, wave direction, and wavelength were conducted. Compared with the steady-state, the transient condition resulted in a deterioration of the combustion efficiency. Furthermore, the amount of unburned fuel, NOX compounds, and brake specific fuel consumption have increased.

Improved body force propulsion model for ship propeller simulation

Body force propulsion model has been used for ship self-propulsion CFD simulation for a long time due to its higher computational efficiency and less computer source required. This paper presents a new body force method coupled the blade element momentum theory (BEMT) considering the three-dimensional viscous effects with the RANS solvers. In-house code HUST-Ship was used to solve RANS equations with finite difference method and PISO arithmetic for propulsion model and ship hydrodynamic simulation. KP505 propeller and KCS ship model were used as the numerical model for the studies. Open water characteristics of discretized propeller model were obtained after uncertainty analysis of CFD results. The lift coefficients CL and the drag coefficients CD of different radius sections on the propeller blade were obtained from CFD results of open water characteristics. The multivariate regression method was used to get the correlations between CL, CD and propeller parameters for a propeller model. Then the BEMT method would adopt the correlations with the local velocity at the virtual disk from CFD simulation results simultaneously to calculate the thrust and torque distributions on the blade and thrust and torque of the propulsion model were obtained with integration along the blade. The comparisons of open water characteristics of CFD results between three different body force models and discretized propeller model were performed. The CFD simulation for open water characteristics and velocity distribution around propulsion models are almost same for new body force model and discretized propeller model. The self-propulsion simulations of KCS with new body force model were performed. The comparisons of the KCS self-propulsion simulations results with new body force model, discretized propeller model and EFD results showed good matches with each other.

Analysis of thrust-induced sail plane coning and attitude motion of electric sail

This paper investigates the dynamic characteristics of thrust-induced sail plane coning and attitude motion of an electric solar wind sail (E-sail) by considering high-order modes of flexible elastic tethers. The tethers of the E-sail are assumed elastic and discretized into inter-connected 2-noded tensile elements using the nodal position finite element method, while the central spacecraft and the remote units are simplified as lumped masses. The E-sail is assumed in the heliocentric ecliptic orbital plane at a distance of 1 au from the Sun. The influences of the propulsive force models and the initial E-sail orientation on the dynamic characteristics of the sail plane coning and attitude motion of E-sail are analyzed. The current work derives an analytic expression of the coning motion frequency under the assumption of small coning angle. Through parametric analyses, the current work shows that the magnitude of the propulsive force significantly influences the increment magnitude of the E-sail's orbital radius while has little effect on the angles of sail and thrust angles and the E-sail spin rate. The parametric analyses also show that the initial E-sail orientation significantly influences the thrust vector and the variation of sail angle. Finally, the relationships of the sail and thrust angles, as well as the dimensionless acceleration of the E-sail, are given in polynomial expressions by curve-fitting of simulation results of E-sails with the consideration of coning motion. The relationships are compared with the previous results of E-sails without including coning motion. It shows the coning motion has negligible effect on the macro dynamic behaviors of E-sail.

Компьютерное моделирование судовой электроэнергетической системы с вентильно-индукторным гребным электроприводом

<b>Object and purpose of research. </b>This paper discusses an electric propulsion (EPS) system with switched-reluctance motor (SRM) to develop and verify the computer-based model of SRM propulsion drive and investigate voltage harmonics in an SRM-powered marine EPS. <br><b> Subject matter and methods.</b>The study was performed on a computer-based model of EPS as per common circuit simulation methods for electric power systems and their elements. <br><b>Main results. </b>This work included development and validation of a computer-based circuit model of an SRM propulsion drive. It identified of voltage and current harmonics in drive elements and estimated the effect of assumptions upon the deviations between calculation results and experimental data, with calculation of main switchboard (MSB) voltage nonsinusoidality ratio in an EPS with synchronous generator and SRM propulsion drive of commensurable capacity. The study also outlined the ways for further improvement of harmonics. <br><b> Conclusion. </b>Computer-based circuit model of SRM propulsion drive enables sufficiently accurate calculation of transitory and steady processes taking place in switched-reluctance motor. Simulated electromagnetic processes in the system, as well as power exchange between phase windings and DC link of commuting converter correspond to the real ones. This model could be used to investigate the effect of SRM drive operation conditions upon EPS power quality that might be further improved by the optimization of control pulse duration ratios for phase module keys.

Free running computations of KCS with different propulsion models

Computations of the self-propulsion free running KCS model with 2DOF (heave and pitch) using four different propulsion models are presented. Computations are performed with HUST-Ship, in house URANS CFD code developed for ship hydrodynamics. PI speed controller is used to find the propeller rotational speed that could balance the thrust and resistance. Single-phase level-set approach is used for free surface simulation. Propulsion models include discretized propeller, the descriptive body force based on open water curve and simple Hough and Ordway approach, OUM (Osaka University Method) based on simplified quasi-steady two-dimensional BEMT (blade element momentum theory) and modified OUM based on BEMT considering three-dimensional viscous effects. Compared with OUM, modified OUM obtained the CL and CD from discretize propeller model open water characteristic CFD computation results so that the method could be more similar to the discretize propeller model. The computation conditions are same as the model test and the computational results show good match with model test data. The results show that considering the three-dimensional viscous effect of propellers can improve the simulation accuracy of propulsion model. The CFD computation results of open water characteristics show the modified OUM has less than 2% difference compared with the discretized propeller models and higher prediction accuracy than OUM. The self-propulsion free running computational results of thrust, velocity distribution, free-surface cuts and self-propulsion parameters using modified OUM model have been compared with EFD and discretized propeller model.