Propulsion System Design Research Articles

A recent approach to the research on axial oscillation of shaft system on ships

In the design of ship propulsion system, the study of oscillation is a great importance because they play a decisive role in the operating ability of the shaft system. Among ship shaft oscillations, axial oscillation has been only a particular interest after applying on ships for diesel engines with ratio of piston stroke and its diameter 3-4,4. In this paper, the special features of the computational model are presented when studying the axial oscillations on the ship shaft system. It should be emphasized that the system of differential equations in describing the free and forced oscillations can be obtained directly from the analogous equations of the torsion oscillation. However, unlike the torsional oscillation, the axial oscillation of the ship shaft system directly affects the hull through the thrust bearing. In order to solve with the problem of determining the forced and resonant axial oscillations based on the Runge-Kutta numerical method is done by directly integrating the system of 2nd order differential equations in describing the oscillations. Therefore, the paper presents the research results in proposing a procedure to reduce the order of 2nd order differential equations and providing an algorithm to solve the system of differential equations in describing axial oscillations. From that, it will be considered that the mechanism under which forces of variable value are applied to it, axial oscillation occurs. The accuracy in calculating of the axial oscillation depends not only on the accepted method of determining the free and forced oscillation, but also the proper in giving the parameters of the discrete model. If the masses are easy to calculate, the evaluation of the axial deformation of the crankshaft is not univariate because there are many formulas given on the basis of idealizing the crankshaft under the structure of bar. Hence, it is proposed to build a 3D model and determine the deformation of the engine crankshaft components by the finite element method.

Proposal of unmanned ground vehicle powered by fuel cell

The presented article deals with the design of an unmanned ground vehicle (UGV) with electric drive, using a fuel cell as a source of electricity. The introduction describes the principle of the fuel cell, followed by the design of the UGV propulsion system. The UGV design, taking into account specific technical parameters, is processed into a model in the simulation environment MATLAB / Simulink / Simscape. Simulation results are presented in graphical form of selected physical quantities over time.

Improvement of Electric Aircraft Endurance through Propeller Optimization via BEM-CFD Methodology

An exhaustive optimization method is developed to minimize the power consumption for a propeller-driven electrical aircraft. The method finds the optimal value for a wide range of geometrical and operational parameters for a target thrust and airspeed. The optimization routine employs BEM for propeller predictions fed with aerodynamic airfoil data obtained from a proposed combined CFD-Montgomerie method which is also validated, furthermore several corrections to account for compressibility, three dimensional, viscous and Reynolds number effects are implemented. This BEM model showed an adequate fitting with experimental data. Additionally, Goldstein optimization via Vortex Theory is employed to design pitch and chord distributions minimizing the induced losses of the propeller. The optimization algorithm is validated through a study case where an existent optimization problem is approached leading to very similar results. Some trends and insights are obtained and discussed from the study case regarding the design of an optimal propulsion system. Finally, CFD simulations of the study case are carried out showing a slight relative error of BEM.

Design and analysis of actuator system of electromagnetic shell with high-overload resistances

The components of an electromagnetic shell system should be able to sustain the impact of high-strength instantaneous acceleration when the system is launched. The dynamic characteristics of high overload present significant challenges in the component (electronic and mechanical) design and part assembly of a steering gear system. This paper proposes a new design strategy for the servo system of a high-overload electromagnetic projectile. First, according to the special environment index parameters of a high-overload electromagnetic shell steering system, a new anti-overload deceleration mechanism that combines a triangular thread lead screw, a shift fork, and the entire anti-high-overload mechanical structure is proposed. The transient dynamic vibration characteristics of the entire high overload are analyzed. Based on the integrated module method for complex mechanical and electrical equipment, a mathematical model of the full closed-loop electromagnetic shell actuator system is established, and its dynamic characteristics are analyzed. Finally, a prototype of the high-overload electromagnetic projectile steering system is manufactured. By testing the maximum rudder deflection angle and the frequency and step responses of the system, the dynamic characteristics of the new high-overload electromagnetic shell actuator system are verified. This study provides a new method for designing high-overload electromagnetic shell steering gears.

Optimization of Micro-Thruster Cold Gas Propulsion System Design for Space Applications

Comparing the complexity of the hardware and the control system, cold gas micro thrusters are much more simplified than other propulsion thrusters. Numerical calculation was carried out for mass requirement, mass flow rate, valves, feed system and computational fluid dynamics with finite element analysis was used for tank, pipe and nozzle design. Four different materials: Structural steel, Stainless steel, Aluminum and Titanium, were considered for tank design. They were subjected to the same conditions for four different tank geometries. The propulsion system was designed to be able to produce between 1 and 2 minutes of continuous thrust and the sudden impulses of between 0.8 and 1 seconds of gas expulsion, with over 20 impulses as desired thrust time. The mass and the volume needed for multiple tank geometries, concepts, and materials were determined. The main performance characteristics of the micro thrusters evaluated were Pressure Distribution, Velocity Profile, Temperature Distribution, Nozzle Efficiency and the corresponding Mach Number Distribution. This work is to provide a stable and controllable platform for testing equipment that can be ultimately applied to space applications.

Industry 4.0: smart test bench for shipbuilding industry

Industry 4.0 promises to increase the efficiency of production plants and the quality of the final product. Consequently, companies that implement advanced solutions in production systems will have a competitive advantage in the future. The principles of Industry 4.0 can also be applied to shipyards to transform them into “smart shipyards” (Shipyard 4.0). The aim of this research is to implement an interactive approach by Internet of Things on a closed power-loop test bench equipped with sophisticated sensors that is specifically designed to test high-power thrusters before they are installed on high-speed crafts, which are used in passenger transport. The preliminary results of the proposed Internet of Things-platform demonstrates the efficacy of the decision-making support tool in improving the design of propulsion systems and increasing their efficiency compared to traditional systems.

Research on Intelligent Matching Technology of Marine Electric Propulsion System Based on Fuzzy Multiple Decision Making

Based on matching process of ship electric propulsion system and the fuzzy multiple decision technology, an intelligent matching method of ship electric propulsion system is proposed with the establishment method of factor set, decision set and fuzzy linear transformation in line with the ship electric propulsion system. The decision result from this method is found to be dependent on the maximum membership principle or the score system. By an example, the fuzzy multiple decision-making method is simple in calculation, in line with actual situation and also provides a guidance in the design of ship electric propulsion system. Further related methods and directions are discussed in the end.

Design of an Upper Stage Propulsion System by Multi Objective Hybrid PSO

بلوک‌های انتقال مداری وظیفه‌ی انتقال ماهواره‌ها از مدار پارکینگ به سایر مدارهای هدف را دارند، در این مقاله به طراحی چند موضوعی بهینه یکی از مهم‌ترین زیر سیستم‌های آن یعنی زیرسیستم پیشرانش و از نوع دومؤلفه‌ای مایع، به‌صورت چندهدفه مبتنی بر حداقل جرم و حداکثر ضربه مخصوص پرداخته شده و درنهایت به مقایسه هزینه‌ای آن نیز اشاره‌ای گردیده است. برای ترکیب‌های NTO (اکسید نیتروژن) به‌عنوان اکسیدانت و سوخت‌های UDMH ، MMH ، Hydrazine و RP-1 (کراسین-نوع1) و برای سازه‌های معمول مورد استفاده در این سیستم‌ها طراحی و بهینه‌سازی توسط الگوریتم ازدحام ذرات (PSO ) هیبریدی چند هدفه صورت گرفته است.

Analytical model for electrohydrodynamic thrust.

Electrohydrodynamic (EHD) thrust is produced when ionized fluid is accelerated in an electric field due to the momentum transfer between the charged species and neutral molecules. We extend the previously reported analytical model that couples space charge, electric field and momentum transfer to derive thrust force in one-dimensional planar coordinates. The electric current density in the model can be expressed in the form of Mott-Gurney law. After the correction for the drag force, the EHD thrust model yields good agreement with the experimental data from several independent studies. The EHD thrust expression derived from the first principles can be used in the design of propulsion systems and can be readily implemented in the numerical simulations.

Design of a Solid Rocket Propulsion System

Design of a Solid Rocket Propulsion System

Simultaneous Combined Optimal Design and Control Formulation for Aircraft Hybrid-Electric Propulsion Systems

A key challenge in the design of hybrid-electric propulsion systems (HEPSs) for aircraft is the complexity involved in handling efficient sizing of the components as well as control synergy between multiple power sources. To handle this challenge effectively, combined optimal design and control (codesign) methods that enable the integration of energy management optimization along with vehicle sizing are required. Even though some studies have explored such methods, they have done so in a computationally intensive nested formulation with limited depth on the design and control modeling aspect. This paper addresses these issues by posing the system codesign problem using a simultaneous formulation of multidisciplinary dynamic system design optimization (MDSDO). The simultaneous formulation generally facilitates superior computational performance while the MDSDO method solves codesign problems from a more balanced perspective between design- and control-related variables. This method is applied in this paper to aircraft HEPS design with an objective of determining the optimal propulsion component designs and supervisory control strategy that minimizes total energy consumption. The hybrid configuration is compared with its conventional counterpart on the basis of system efficiency. In addition to that, a parametric study on the battery energy density is presented to explore the near-term viability of HEPS for aircraft.

The Analysis of Biomimetic Caudal Fin Propulsion Mechanism with CFD.

In nature, fish not only have extraordinary ability of underwater movement but also have high mobility and flexibility. The low energy consumption and high efficiency of fish propulsive method provide a new idea for the research of bionic underwater robot and bionic propulsive technology. In this paper, the swordfish was taken as the research object, and the mechanism of the caudal fin propulsion was preliminarily explored by analyzing the flow field structure generated by the swing of caudal fin. Subsequently, the influence of the phase difference of the heaving and pitching movement, the swing amplitude of caudal fin, and Strouhal number (St number) on the propulsion performance of fish was discussed. The results demonstrated that the fish can obtain a greater propulsion force by optimizing the motion parameters of the caudal fin in a certain range. Lastly, through the mathematical model analysis of the tail of the swordfish, the producing propulsive force principle of the caudal fin and the caudal peduncle was obtained. Hence, the proposed method provided a theoretical basis for the design of a high-efficiency bionic propulsion system.

Evolution and design of propulsion systems for unmanned aerial vehicles: the compromise between payload mass and operational range based on the constructal law of design and evolution

Evolution and design of propulsion systems for unmanned aerial vehicles: the compromise between payload mass and operational range based on the constructal law of design and evolution

Design and Development of Actuator System for Automated Polypropylene Bag Assembly Machine

Polypropylene bags are widely used in many industries especially in agriculture and food industry. However, industries especially in food or fertilizer industries, need to use the polypropylene bags that can withstand a high level of humidity. To overcome this problem, a two-layers bag is required. This two-layers bag consists of outer layer woven bag and inner layer polypropylene bag. Currently they are produced by using conventional method where they are assembled manually by the workers. This manual method causes longer production time process, a high number of workers, and higher cost for mass production. To enhance the operation performance, automated polypropylene bags assembly system is proposed. By using an automated system, it can improve quality and consistency of processes, and reduced direct human labor costs and expenses where the worker is unneeded for assembling the polypropylene bag. To overcome this problem, this project is dedicated to design and develop a new Automated Polypropylene Bag Assembly Machine (APBAM) to operate the process automatically. This machine will execute three main processes - Grasping, Handling and Feeding. This paper will focus on the design of pneumatic actuator for grasping polypropylene bags in upward and downward motion. The design will be calibrated, analyzed and evaluated. The design of automated polypropylene bags assembly system will help to solve some of the problems that have been identified.

Small Vessel with Inboard Engine Retrofitting Concepts; Real Boat Tests, Laboratory Hybrid Drive Tests and Theoretical Studies

The development of modern technologies and their increasing availability, as well as the falling costs of highly efficient propulsion systems and power sources, have resulted in electric or hybrid propulsions systems’ growing popularity for use on watercraft. Presented in the paper are design and lab tests of a prototype parallel hybrid propulsion system. It describes a concept of retrofitting a conventionally powered nine meter-long vessel with the system, and includes results of power and efficiency measurements, as well as calculations of the vessel’s operating range under the propulsion of its electric motor. The concept of adding of a solar panels array was studied.

Investigation of the characteristics of an ion engine with a microwave generator plasma

This paper presents the results of an experimental study of the velocity of ionized nitrogen flowing from the working chamber of an experimental sample of the primary accelerating system of the ion engine into the vacuum space. The main method of research was chosen calorimetric method. The design of a small spacecraft jet propulsion system with ionized gas acceleration in the high-frequency gap of a microwave generator is proposed. The object of the study is a prototype of the primary ion engine accelerator system with a solid-state microwave plasma generator and an accelerating gap. The study showed that a 3-watt microwave generator together with a pulsed voltage source of an accelerating potential difference of 1 W at a nitrogen consumption of 2.5 mg/s creates an ion jet whose speed reaches 30 km/s.the Current of the ion jet was 2-2.5 mkA. The field strength of the accelerating potential difference was 4450 V / m.

Dynamics and combustion of single aluminium agglomerate in solid propellant environment

Aluminized composite propellant used in solid rocket motors contain a lot of aluminium particles because high combustion energy is generated and propulsion efficiency increases by burning aluminium particles. The combustion of aluminum occurs in a significant portion of the combustion chamber and produces aluminum oxide smokes and residues that are carried into the flowfield. Agglomerates have non-spherical shape, and consist of aluminium droplet and oxide particle (oxide cap) attached to the droplet. Unlike the liquid droplet ignition, the solid oxide film blocks the liquid aluminum from the penetration of the oxidizer hence prevents the particle from its ignition. Development of robust models of aluminum particle dynamics is essential in the design of advanced propulsion systems. The mathematical model of two-phase flow around a single aluminum droplet with oxide cap is developed. The model solves the continuity, momentum, energy and species continuity equations simultaneously to obtain the species and temperature profiles and the burning time of droplet. The results of numerical simulations are compared with predictions from semi-empirical correlations and computational data.

Low enriched nuclear thermal propulsion neutronic, thermal hydraulic, and system design space analysis

Nuclear thermal propulsion is the high thrust, high specific impulse rocket engine technology of choice for future missions to Mars and beyond. Current designs are focusing on low enriched uranium fuel systems to reduce development costs and regulatory concerns. These designs require careful examination to identify an engine that is able to satisfy NASA’s requirements. Previous work has focused on low enriched, but for limited cases of fuel options and without a fully integrated computational framework and assumed boundary conditions. The current study relies on and extends previous publicly available NASA studies by accounting for UN fuel embedded in Molybdenum and Molybdenum-Tungsten matrices. Integrated system framework that considers various engine’s components was developed. The performance of the engine is evaluated using T/H analysis of all the major components, such as the reactor-core, pumps, turbines, and pipes. Neutronic calculations are performed using the Serpent code, in which both the neutron and gamma transport were enabled to provide accurate spatial power distributions. The results show that using an integrated system analyses approach yields a systematic assessment and identifies an ideal design space for future higher fidelity analysis to achieve mission needs set by NASA.

Design and Preliminary Evaluation of A Biomimetic Underwater Robot with Undulating Fin Propulsion

Biomimetic undulating fin propulsion systems have the advantages for enhancing the maneuverability and efficiency of underwater robot when compared with conventional driving forms. However, there are still some defects existing in this approach, such as low speed and difficulty in depth control. This paper presents the mechanical design, control system design and experimental evaluation of a biomimetic underwater robot with undulating fin propulsion. First, a 3D model of the robot was established in CATIA. According to the kinematic model of the fins, the design of undulating fin propulsion system have been optimized and the phase control method has been proposed to fit with the design. Next, a control system with hybrid structure switching between autonomous mode and remote mode has been implemented to address the problem that the robot is out of control in underwater environment due to the attenuation of radio signals. Finally, the underwater locomotion performance of the robot has been validated in a swimming pool. The result indicates that the robot can achieve multiple degree of freedoms (DOFs) motions by controlling the kinematic parameters of the fin and was able to swim as fast as 31.6 cm/s (nearly 0.8 body length per second).

Design and development of prototype carpal wrist cold gas propulsion system for attitude control applications

In recent years, the Philippine space program has launched several small-scale satellites, and lately has commissioned its own space program. Research on improving the subsystems of these satellites would be beneficial to future space programs in the Philippines. This paper will detail the process of designing, validating, fabricating, and testing a prototype Carpal Wrist Cold Gas Propulsion System (CW-CGPS). By making use of a carpal wrist’s (CW) hemispherical movement capabilities, the sixteen thrusters could theoretically be replaced by four mounted on opposite ends. Optimization of the propulsion system is based on finding the nozzle design with the most adequate values for thrust, Mach number, and specific impulse while the CW design is validated when it can be calibrated to move as the program dictates. This study uses multiple programs to simulate and verify the design. The conditions of the testing environment are established by resources from international space organizations. Assembly and feasibility are assessed based on the results of the research. It was found that the final optimized system had a model torque of 0.247 N-m, more than enough to overcome the maximum combined influence of the gravity gradient torque of 2.34E-06 N-m and aerodynamic torque of 1.57E-25 N-m. The design, development, and test campaign for the thruster system is presented.