scholarly journals Laser–Accelerated Plasma–Propulsion System

2021 ◽  
Vol 11 (21) ◽  
pp. 10154
Author(s):  
Daniele Palla ◽  
Gabriele Cristoforetti

In this paper, the laser-accelerated plasma–propulsion system (LAPPS) for a spacecraft is revisited. Starting from the general properties of relativistic propellants, the relations between specific impulse, engine thrust and rocket dynamics have been obtained. The specific impulse is defined in terms of the relativistic velocity of the propellant using the Walter’s parameterization, which is a suitable and general formalism for closed–cycle engines. Finally, the laser-driven acceleration of light ions via Target Normal Sheath Acceleration (TNSA) is discussed as a thruster. We find that LAPPS is capable of an impressive specific impulse Isp in the 105 s range for a laser intensity I0≃1021W/cm2. The limit of Isp≲104 s, which characterizes most of the other plasma-based space electric propulsion systems, can be obtained with a relatively low laser intensity of I0≳1019W/cm2. Finally, at fixed laser energy, the engine thrust can be larger by a factor 102 with respect to previous estimates, making the LAPPS potentially capable of thrust-power ratios in the N/MW range.

2021 ◽  
Vol 20 (3) ◽  
pp. 65-76
Author(s):  
V. V. Salmin ◽  
V. V. Volotsuev ◽  
A. V. Nikitin

An analysis of the mass of the working fluid and motor operating time of electric propulsion systems applied as a part of small spacecraft to carry out maneuvers of maintenance of the low Earth working orbit is carried out. The analysis is carried out for the small spacecraft with the weight in the range from 300 to 1000 kg functioning in working orbits with the height in the range from 400 to 600 km. When carrying out the analysis the values of the specific impulse of the propulsion system in the range from 800 to 1600 sec were accepted. Procedural guidelines for assessing the value of the required characteristic speed depending on the aerodynamic drag force, as well as for assessing the value of mass of the working fluid with account for the value of the specific impulse and defining the motor operating time of the propulsion system depending on the exhaust speed of the working fluid were used. The results of calculations given in the article show that the mass of the working fluid and the motor operating time vary depending on the height of the orbit and the mass of the small spacecraft and allow making quick preliminary assessment of the main design characteristics of the electric propulsion engines used to carry out maneuvers of maintenance of the low Earth working orbit of small spacecraft with different weight dimension characteristics during the prescribed term of active existence.


Author(s):  
Nicolas Bellomo ◽  
Mirko Magarotto ◽  
Marco Manente ◽  
Fabio Trezzolani ◽  
Riccardo Mantellato ◽  
...  

AbstractREGULUS is an Iodine-based electric propulsion system. It has been designed and manufactured at the Italian company Technology for Propulsion and Innovation SpA (T4i). REGULUS integrates the Magnetically Enhanced Plasma Thruster (MEPT) and its subsystems, namely electronics, fluidic, and thermo-structural in a volume of 1.5 U. The mass envelope is 2.5 kg, including propellant. REGULUS targets CubeSat platforms larger than 6 U and CubeSat carriers. A thrust T = 0.60 mN and a specific impulse Isp = 600 s are achieved with an input power of P = 50 W; the nominal total impulse is Itot = 3000 Ns. REGULUS has been integrated on-board of the UniSat-7 satellite and its In-orbit Demonstration (IoD) is currently ongoing. The principal topics addressed in this work are: (i) design of REGULUS, (ii) comparison of the propulsive performance obtained operating the MEPT with different propellants, namely Xenon and Iodine, (iii) qualification and acceptance tests, (iv) plume analysis, (v) the IoD.


2019 ◽  
Vol 7 (6) ◽  
pp. 168
Author(s):  
Hyeonmin Jeon ◽  
Jongsu Kim ◽  
Kyoungkuk Yoon

In the case of the electric propulsion system on the vessel, Diode Front End (DFE) rectifiers have been applied for large-sized ships and Active Front End (AFE) rectifiers have been utilized for small and medium-sized ships as a part of the system. In this paper, we design a large electric propulsion ship system using AFE rectifier with the proposed phase angle detector and verify the feasibility of the system by simulation. The phase angle derived from the proposed phase angle detection method is applied to the control of the AFE rectifier instead of the zero-crossing method used to detect the phase angle in the control of the conventional AFE rectifier. We compare and analyze the speed control, Direct Current (DC)-link voltage, harmonic content and measurement data of heat loss by inverter switch obtained from the simulation of the electric propulsion system with the 24-pulse DFE rectifier, the conventional AFE rectifier, and the proposed AFE rectifier. As a result of the simulation, it was confirmed that the proposed AFE rectifier derives a satisfactory result similar to that of a 24-pulse DFE rectifier with a phase shifting transformer installed according to the speed load of the ship, and it can be designed and applied as a rectifier of a large-sized vessel.


Author(s):  
Ioannis Roumeliotis ◽  
Lorenzo Castro ◽  
Soheil Jafari ◽  
Vassilios Pachidis ◽  
Louis De Riberolles ◽  
...  

Abstract Future aircraft and rotorcraft propulsion systems should be able to meet ambitious targets and severe limitations set by governments and organizations. These targets cannot be achieved through marginal improvements in turbine technology or vehicle design. Hybrid-electric propulsion is being widely considered as a revolutionary concept to further improve the environmental impact of air travel. One of the most important challenges and barriers in the development phase of hybrid-electric propulsion systems is the Thermal Management System (TMS) design, sizing and optimization for addressing the increased thermal loads due to the electric power train. The aim of this paper is to establish an integrated simulation framework including the vehicle, the propulsion system and the fuel-oil system (FOS) for assessing the cooling capability of the FOS for the more electric era of rotorcrafts. The framework consists of a helicopter model, propulsion system models, both conventional and hybrid-electric, and a FOS model. The test case is a twin-engine medium (TEM) helicopter flying a representative Passenger Air Transport (PAT) mission. The conventional power plant heat loads are calculated and the cooling capacity of the FOS is quantified for different operating conditions. Having established the baseline, three different Power Management Strategies (PMS) are considered and the integrated simulation framework is utilized for evaluating FOS temperatures. The results highlight the limitations of existing rotorcraft FOS to cope with the high values of thermal loads associated with hybridization for the cases examined. Hence, new ideas and embodiments should be identified and assessed. The case of exploiting the fuel tank as a heat sink is investigated and the results indicate that recirculating fuel to the fuel tank can enhance the cooling capacity of conventional FOS.


2019 ◽  
Author(s):  
V Bolbot ◽  
G Theotokatos ◽  
E Boulougouris ◽  
D Vassalos

Cruise ship industry is rapidly developing, with both the vessels size and number constantly growing up, which renders ensuring passengers, crew and ship safety a paramount necessity. Collision, grounding and fire are among the most frequent accidents on cruise ships with high consequences. In this study, a hazard analysis of diesel-electric and hybrid-electric propulsion system is undertaken using System-Theoretic Process Analysis (STPA). The results demonstrate significant increase in potential hazardous scenarios due to failures in automation and control systems, leading to fire and a higher number of scenarios leading to propulsion and power loss in hybrid-electric propulsion systems than on a conventional cruise-ship propulsion system. Results also demonstrate that STPA enhancement is required to compare the risk of two propulsion systems.


Author(s):  
John C. Bentz

Electrical energy sources offer some interesting possibilies for aircraft propulsion. Of particular interest are electric propulsion systems developed for aircraft that are designed for high altitude, long endurance (HALE) missions. This class of aircraft would greatly benefit from an aircraft propulsion system which minimizes thermal energy rejection and environmental pollutants. Electric propulsion systems may prove viable for the HALE mission, if reliable energy sources can be developed that are both fuel and weight efficient. Fuel cells are a possible energy source. This paper discusses the thermodynamic cyclic analysis of a fuel cell powered electric propulsion system. In particular, phosphoric acid and polymer electrolyte fuel cells are evaluated as possible energy sources.


Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 455
Author(s):  
Bowen Zhang ◽  
Zaixin Song ◽  
Fei Zhao ◽  
Chunhua Liu

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.


Aerospace ◽  
2019 ◽  
Vol 6 (9) ◽  
pp. 99 ◽  
Author(s):  
Fabrizio Stesina

Miniaturized electric propulsion systems are one of the main technologies that could increase interest in CubeSats for future space missions. However, the integration of miniaturized propulsion systems in modern CubeSat platforms presents some issues due to the mutual interactions in terms of power consumption, chemical contamination and generated thermal and electro-magnetic environments. The present paper deals with the validation of a flexible test platform to assess the interaction of propulsion systems with CubeSat-technologies from mechanical, electrical, magnetic, and chemical perspectives. The test platform is a 6U CubeSat hosting an electric propulsion system and able to manage a variety of electric propulsion systems. The platform can regulate and distribute electric power (up to 60 W), exchange data according to several protocols (e.g., CAN bus, UART, I2C, SPI), and provide different mechanical layouts in 4U box completely dedicated to the propulsion system. Moreover, the data gathered by the onboard sensors are combined with the data from external devices and tools providing unprecedented information about the mutual behavior of a CubeSat platform and an electric propulsion system.


Author(s):  
Michael Schneider ◽  
Jens Dickhoff ◽  
Karsten Kusterer ◽  
Wilfried Visser

Abstract In the recent decades, civil aviation was growing 4.7% per annum. In order to reduce emissions promoting the global warming process, alternative propulsion systems are needed. Full-electric propulsion systems in aviation might have the potential for emission-free flights using renewable energy. However, several research efforts indicate electric propulsion only seems feasible for small aircraft. Especially due to the low energy density of batteries compared to fossil fuels. For this reason, hybrid propulsion systems came into focus, combining the benefits of all-electric and conventional propulsion system concepts. It is also considered as bridging technology, system test and basis for component development — and therewith paves the way towards CO2 free aviation. In the ‘HyFly’ project (supported by the German Luftfahrtforschungsprogramm LuFo V-3), the potential of a hybrid electric concept for a short/mid-range 19 PAX aircraft is assessed — not only on system but also on single component basis. In a recent study, the propulsion architecture and the operating mode of the gas turbine and the electric components have been defined [1]. In this paper, the advantages of the hybrid propulsion architecture and a qualitative assessment of component life are presented. Methods for life time prediction for the aircraft engine, the electric motor, the reluctance generator and the battery are discussed. The impact of turbine inlet temperature on life consumption is analyzed. The life cycle of the aircraft engine and the electric components including gradual component deterioration and consequent performance degradation is simulated by using an in-house gas turbine simulation tool (GTPsim). Therefore, various effects on electric propulsion system can be predicted for the entire drivetrain system in less than one hour.


2021 ◽  
pp. 1-19
Author(s):  
Yi Zhou ◽  
Kayvan Pazouki ◽  
Rosemary Norman

Abstract With the effects of global warming, the North Sea Route has become an economic option for cargo transportation because of the shorter distance between East Asia and Europe. Generally, conventional mechanical propulsion systems installed in ice-capable tankers suffer from significant drawbacks because of poor fuel efficiency when sailing at low speed, therefore, advanced technologies have been applied such as diesel electric and nuclear-powered propulsion; however, drawbacks still exist. Hybrid propulsion is a more environmental-friendly, economical solution for ships with icebreaking capability, which can address the drawbacks in both diesel electric and nuclear power systems. In this paper, modeling of system components is presented and implemented in MATLAB Simulink. A primary control strategy is applied to the system to ensure system stability, and an advanced secondary strategy is developed and applied to the power sources to minimize fuel consumption. Given two scenarios, the simulation results of the hybrid propulsion system developed in this research and those of diesel electric propulsion systems with DC and AC distribution systems are compared and indicate that the hybrid system can offer up to 22.4% fuel savings over ice-loading condition, and 39.5% fuel reduction over the particular voyage of varying speed in open water is applied in this paper. Introduction In recent years, some sea routes that were previously blocked by ice have become increasingly accessible in the warmest months of the year due to the effects of global warming. Researchers have estimated that, by 2030, the percentage of Arctic shipping will have increased to 25% of cargo trade between Europe and Asia (Lasserre 2019). Northern Sea Route (NSR) shipping provides benefits for international trade, but challenges still exist. Increasing carbon emissions have seriously impacted the Arctic environment (Hassol & Corell 2006). Table 1 shows the total number of ships using Heavy Fuel Oil (HFO) in Arctic waters in 2015, and associated black carbon emissions, as published by the IMO (Comer et al. 2017). As it is shown, oil tankers made up just 4.5% of all ships entering Arctic waters but despite their low proportion, they were responsible for 17% of black carbon emissions. Thus, an environmentally friendly and fuel-efficient propulsion system to reduce these emissions from tankers trading in Arctic waters is required.


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