Identification results of an internal combustion engine as a quadrotor propulsion system

Author(s):  
Tomislav Haus ◽  
Marko Car ◽  
Matko Orsag ◽  
Stjepan Bogdan
Author(s):  
Young Seok Kang ◽  
Dong Ho Rhee ◽  
Byeung Jun Lim ◽  
Sangook Jun ◽  
Tae Choon Park ◽  
...  

A turbo-compression system design and its performance analysis procedure for a high altitude long endurance UAV (HALE UAV), of which cruising altitude is within the stratosphere, is presented. To fly at a relatively low speed for a long time and to make engine performance less sensitive to flight altitude, a hydrogen fueled internal combustion engine was chosen for a propulsion system. To utilize an internal combustion engine as a propulsion system at a high altitude, a proper inlet pressure boost system such as a series of turbochargers is required. Hydrogen is highly reactive gas and sometimes backfiring or preignition may occur due to its low ignition energy at stoichiometric ratio. Therefore, fuel to air ratio should be reduced as low as 0.6 to avoid such phenomena. Then rarefied ambient intake air pressure should be boosted up to 1.7 bar to produce required power from the lean burn engine. To gain high pressure ratio from the turbo compression system, at least three stage serial turbocharger with proper intercooler system at each compressor exhaust is required. To analyze multi-stage turbocharger performance at the cruising altitude, an explicit one-dimensional analysis method has been established mainly by matching required power between compressors and turbines. Each compressor performances were corrected according to Reynolds number at a given flight altitude. Compressor efficiency and surge margin deteriorate as the operating altitude increases. Then compressor efficiencies were reflected as functions of flight altitude and corresponding Reynolds number. Once operating points of each turbocharger was determined, then adequate turbochargers were searched for from commercially available models based on performance analysis results. Also, adequate water to air intercoolers were chosen for the turbo-compression system to secure flexibility of placing main components inside the engine bay as well as to obtain high heat exchange efficiency of the heat exchangers. Based on the designed turbo-compression system, technical demonstration test of the turbo-compression system inside altitude environment test chamber in Korea Aerospace Research Institute is planned. Altitude condition in stratosphere is simulated mainly with two stage centrifugal compressor and additional fan will be used to fine control the flight altitude. The turbo compression system will be controlled with a single waste gate located just downstream of the engine to secure simple controllability of the turbo compression system. The test results will validate main components as well as system layout design methods and give more reliable control schedule of the turbo compressions system according to the flight altitude.


2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Vu Tran Tuan ◽  
Phuong Nguyen Huy ◽  
Surasak Phoemsapthawee ◽  
Sangkla Kreuawan

An Electric propulsion (E-propulsion) system for ASEAN (Association of Southeast Asian Nations) long-tail boat is proposed in this article. It offers several advantages over a traditional internal combustion engine propulsion system. Besides low noise and zero-emission, characteristics of electric engine (E-engine) allow regenerative braking and starting the propeller in the water. A design of E-engine has been achieved through finite element analyses and lump-parameter thermal simulations. It shows better performances than Honda GX270 internal combustion engine in terms of volume, weight, torque, and power. A full scale prototype of E-engine was manufactured. Experiments have been conducted on an engine test bench. Torque, power, efficiency and temperatures were well aligned with the simulation results.


Author(s):  
Davide Tarsitano ◽  
Laura Mazzola ◽  
Federico Cheli ◽  
Ferdinando Mapelli

The use of road vehicles has always represented a major contribution to the growth of modern society: it facilitates goods and people mobility, meeting most of the daily needs and it represents a backbone for the development of world economy, (i.e. the industrial field). Nowadays, this mean of transportation, however, given the high number of vehicles on the roads, has a negative impact both on the environment and on the quality of human life. Moreover it leads to an increase in additional costs (i.e. the costs related to environment pollution, global warming and depletion of resources). Such a negative aspect is due to the fact that the drive systems are often characterized by high variability of the load, hence the propulsion system works in areas with low efficiencies and high pollutant emissions. In order to overcome these problems, and to allow the compliance of the road transport system with new European guidelines (i.e White paper, and Horizon 2020), it is necessary to develop innovative technologies able to: - increase the overall powertrain efficiency; - introduce a sustainable alternative fuels strategy including also the appropriate infrastructure; - reduce carbon emission through a decarbonisation approach; In this perspective, in recent years, the technology of electric and hybrid vehicles has been developed, and nowadays it has become a feasible solution in the context of means of transportation. Car/truck-makers and operators look at further developments and innovation in this field in order to optimise the existing solutions and reduce the production costs. The current solution for hybrid vehicles aims to couple a conventional engine with an electrical motor; these two propulsion system are coordinated by an opportune algorithm in order to let the conventional engine operate in its higher efficiency range. Hence the technology foresees the action of endothermic and electrical motors. It is then pivotal for the success of this transport the optimisation of the whole system (electrical and endothermic) in terms of efficiency, sizing and of the control algorithm that coordinate the two propulsion systems. For the modeling of the internal combustion engine conventional approaches, based on the numerical simulation of the combustion process, cannot be used because of their complexity in term of time needed for computing activity. For hybrid power train the general approach to simulated a drive cycle, that usually last at least a few minutes, is based on engine map approach [1–2]. The main burden to the described process is the identifications of maps of torque and consumption for the internal combustion engine, which are normally not predictable in detail, nor are provided by the manufacturers, but they can only be determined by means of experimental tests. Such a process can become extremely expensive and time consuming. Hence in this work the concept of virtual optimisation is introduced basing on the identification of torque and fuel consumption maps for internal combustion engines on analytical methods considering the similarities with engine of the same class. In this regard, a model of the system is developed based on the “Willans Line Method” approach, subsequently to a theoretical definition of the model, the identification of maps is carried out for two different engines (one diesel heavy-duty engine and one spark ignition engine) in order to consider the existing configurations of hybrid vehicles. Eventually the calculated maps are validated considering experimental data from existing experimental campaign. Providing the validity of the method and its usefulness in the hybrid vehicle design.


Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.


Author(s):  
Oleksandr Gryshchuk ◽  
Volodymyr Hladchenko ◽  
Uriy Overchenko

This article looks at some comparative statistics on the development and use of electric vehicles (hereinafter referred to as EM) as an example of sales and future sales forecasts for EM in countries that focus on environmental conservation. Examples of financial investments already underway and to be made in the near future by the largest automakers in the development and distribution of EM in the world are given. Steps are taken to improve the environmental situation in countries (for example, the prohibition of entry into the city center), the scientific and applied problem of improving the energy efficiency and environmental safety of the operation of wheeled vehicles (hereinafter referred to as the CTE). The basic and more widespread schemes of conversion of the internal combustion engine car (hereinafter -ICE) to the electric motor car (by replacing the gasoline or diesel electric motor), as well as the main requirements that must be observed for the safe use and operation of the electric vehicle. The problem is solved by justifying the feasibility of re-equipment of the KTZ by replacing the internal combustion engine with an electric motor. On the basis of the statistics collected by the State Automobile Transit Research Institute on the number of issued conclusions of scientific and technical expertise regarding the approval of the possibility of conversion of a car with an internal combustion engine (gasoline or diesel) to a car with an electric motor (electric vehicle), the conclusions on the feasibility of such conclusion were made. Keywords: electricvehicles, ecological safety, electricmotor, statistics provided, car, vehicle by replacing.


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