• Title/Summary/Keyword: electric vehicle

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Analysis of Ventilating Seat Comfort Temperature for Improving the Thermal Comfort inside Vehicles (자동차 실내 열쾌적성 개선을 위한 통풍시트의 쾌적온도 분석)

  • In, Chung-Kyo;Kwak, Seung-Hyun;Kim, Chang-Hoon;Kim, Kyu-Beom;Jo, Hyung-Seok;Seo, Sang-hyeok;Myung, Tae-Sik;Min, Byung-Chan
    • Science of Emotion and Sensibility
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    • v.23 no.4
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    • pp.33-40
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    • 2020
  • As the number of automobile registrations increases and luxury expectations grow, consumers are increasingly interested in indoor environment of vehicles. Therefore, manufacturers have an increasing interest in improving the indoor comfort as well as automobile performance. Research on indoor automobile comfort can help manufacturers increase driver satisfaction and reduce driver stress and discomfort, thereby reducing the risk of traffic accidents. Using electroencephalogram (EEG) measurements, we investigated the change in comfort and comfortable temperature according to the ventilating seat temperature change for both men and women. Results showed that the sensation of comfort was statistically significantly higher at 25℃ than at 28℃. Secondly, there was no statistically significant difference in temperature-based comfort feeling between male and female subjects. In the future, if the correlation between the driver's comfort feeling and the change in ventilating seat temperature is analyzed, it is possible to reduce traffic accidents caused by human error and reduce the electric energy consumption of the automobile.

A numerical analysis study on the flammable volume by leakage of hydrogen fuel vehicles in parking lot (지하주차장 내 수소연료차의 수소 방출시 가연체적에 관한 수치해석적 연구)

  • Lee, Ho-Hyung;Kim, Hyo-Gyu;Yoo, Ji-Oh;Kim, Doo-Young
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.6
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    • pp.439-449
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    • 2021
  • The recent reduction in greenhouse gases, interest in environmental pollution such as low-carbon emission policies is increasing. Accordingly, the penetration rate of eco-friendly vehicles, including hydrogen battery vehicles capable of reducing carbon emission, is increasing, and thus it is required for disaster prevention and safety-related measures. In this study, the degree of risk for the concentration distribution of hydrogen when leaking hydrogen fuel vehicles according to ventilation conditions was analyzed through numerical analysis, limited to places in parking lots. As a result, when only one hydrogen tank was released, the combustible volume ratio of hydrogen in the underground parking lot was up to 8.6%, and as ventilation continued, the volume ratio of combustible hydrogen decreased to less than 1% after 150 seconds, indicating that mechanical ventilation is essential. In the case of simultaneous release or stage release of three hydrogen tanks, the final combustible volume ratio of hydrogen is similar, but the increase in the combustible volume ratio of hydrogen in the early stage of release is low, and further research is expected.

Rotordynamic Performance Measurements and Predictions of a FCEV Air Compressor Supported on Gas Foil Bearings (가스 포일 베어링으로 지지되는 연료전지 전기자동차용 공기압축기의 회전체동역학적 성능 측정 및 예측)

  • Hwang, Sung Ho;Moon, Chang Gook;Kim, Tae Ho;Lee, Jongsung;Cho, Kyung Seok;Ha, Kyoung-Ku;Lee, Chang Ha
    • Tribology and Lubricants
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    • v.35 no.1
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    • pp.44-51
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    • 2019
  • The paper presents the rotordynamic performance measurements and model predictions of a fuel cell electric vehicle (FCEV) air compressor supported on gas foil bearings (GFBs). The rotor has an impeller on one end and a thrust runner on the other end. The front (impeller side) and rear (thrust side) gas foil journal bearings (GFJBs) are located between the impeller and thrust runner to support the radial loads, and a pair of gas foil thrust bearings are located on both sides of the thrust runner to support the axial loads. The test GFJBs have a partial arc shim foil installed between the top foil and bump strip layers to enhance hydrodynamic pressure generation. During the rotordynamic performance tests, two sets of orthogonally installed eddy-current displacement sensors measure the rotor radial motions at the rotor impeller and thrust ends. A series of speed-up and coast-down tests to 100k rpm demonstrates the dominant synchronous (1X) rotor responses to imbalance masses without noticeable subsynchronous motions, which indicates a rotordynamically stable rotor-GFB system. Finite element analysis of the rotor determines the rotor free-free (bending) natural modes and frequencies well beyond the maximum rotating frequency. The predicted damped natural frequencies and damping ratios of the rotor-GFB system reveal rotordynamic stability over the speeds of interest. The imbalance response predictions show that the predicted critical speeds and rotor amplitudes strongly agree with the test measurements, thus validating the developed rotordynamic model.

Technology Trend Analysis in the Automotive Semiconductor Industry using Topic Model and Patent Analysis (토픽모델 및 특허분석을 통한 차량용 반도체 기술 추세 분석)

  • Nam, Daekyeong;Choi, Gyunghyun
    • Journal of Korea Technology Innovation Society
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    • v.21 no.3
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    • pp.1155-1178
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    • 2018
  • Future automobiles are evolving into movable living spaces capable of eco-friendly autonomous driving. The role of electrically processing, controlling, and commanding various information in the vehicle is essential. It is expected that the automotive semiconductor will play a key role in the future automobile such as self-driving and eco-friendly automobile. In order to foster the automotive semiconductor industry, it is necessary to grasp technology trends and to acquire technology and quality that reflects the requirements in advance, thereby achieving technological innovation with industrial competitiveness. However, there is a lack of systematic analysis of technology trends to date. In this study, we analyzed the technology trends of automotive semiconductors using patent analysis and topic model, and confirmed technologies such as electric cars, driving assistance, and digital manufacturing. The technology trends showed that element technology and technical characteristics change according to technology convergence, market needs, and government regulations. Through this research, it is expected that it will help to make R&D policy for automotive semiconductor industry and to make decision for industrial technology strategy establishment. In addition, it is expected that it will be used effectively in detail research direction and patent strategy establishment by providing detailed classification of technology and trend analysis result of technology.

FEA(Finite Element Analysis) Study for Electronic Hydrogen Regulator of Confidentiality Improvement (전자식 수소레귤레이터 기밀성 향상을 위한 FEA 연구)

  • Son, Won-Sik;Song, Jae-Wook;Jeon, Wan-Jae;Kim, Seung-Mo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.175-181
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    • 2019
  • In the case of a conventional single stage decompression regulator used for large depressurization in the hydrogen fuel cell system of a fuel cell electric vehicle (FCEV), problems can arise, such as pulsation, slow response, hydrogen brittleness, leakage, high weight, and high cost due to high decompression. Most of these problems can be overcome easily using two decompression mechanisms (two-stage structures). In addition, a wide outlet-pressure control range can be secured if an electronic solenoid is applied to the second decompression. Accordingly, it is necessary to improve the precision of the outlet pressure of a two-stage pressure-reducing regulator and develop techniques, such as leakage prevention, durability, light weight, and price reduction. Therefore, to improve the outlet pressure accuracy and prevent leakage, the structural part before and after decompression to improve the air tightness were divided and the analysis was carried out assuming that the valve part was closed (open ratio: 0%) after each initial internal pressure application.

A Study on the Recycle of Carbon Material in Anode of Secondary Battery (이차전지 음극재 탄소 소재 재활용에 대한 연구)

  • Han, Gyoung-Jae;Kim, Yu-Jin;Yoon, Seong-Jin;Kang, Yu-Jin;Jang, Min-Hyeok;Jo, Hyung-Kun;Cho, Hye-Ryeong;Seo, Dong-Jin;Park, Joo-Il
    • Journal of the Korea Organic Resources Recycling Association
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    • v.30 no.4
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    • pp.59-66
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    • 2022
  • Lithium-ion batteries have greatly expanded along with the mobile phone market, and as the electric vehicle business is activated in earnest, they will attract many people's attention even afterwards. Until now, many people have attracted attention to the recovery of valuable metals inside lithium-ion batteries, but graphite, which is mainly used as an anode material, is also worth recycling. Therefore, in order to recover graphite with high purity and valuable metals, graphite that can be used as an anode material of a secondary battery may be generated again through a regeneration process of purifying and separating graphite from a waste lithium-ion battery and recovering electrical characteristics of graphite. This paper describes the process of converting waste graphite into regenerated graphite and the environmental and economic effects of regenerated graphite.

The Mechanical Properties of SMA Concrete Mixture Using Steel Slag Aggregate (제철 슬래그 골재를 이용한 SMA 혼합물의 역학적 특성)

  • Kim, Hyeok-Jung;Na, Il-Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.1
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    • pp.109-116
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    • 2021
  • In order to replace mineral aggregate used as road pavement materials with steel slag aggregate, this present study evaluated mechanical properties of SMA Concrete mixtures using steel slag aggregate as oxidized slag from electric furnace in iron works. The variables of this experiment are the aggregate type of mineral and steel slag and the sieve sized of 10mm and 13mm. The physical properties inclu ding the specific gravity and absorption rate etc. of the slag aggregate mixtu res satisfied the KS standard as asphalt mixtu re. As a resu lt of evalu ating the mechanical properties of the asphalt mixtures, the optimum asphalt content of the slag aggregate mixtures were lower than that of the mineral aggregate mixtures, but other quality standards were all satisfied. In the deformation strength evaluation, the slag aggregate mixtures were measu red slightly higher than that of the mineral aggregate mixtu res, and the dynamic stability test satisfied the 2,000pass/mm standard value in all specimens. And, the moduli of resilient of the slag aggregate mixtures showed an improved value compared with the mineral aggregate mixtures. Therefore, as the resilient rate of the slag aggregate mixtures improved, it is speculated that there will be an effect of improving public performance according to the repeated traffic load of the vehicle.

Experimental Study on Aerodynamic Performance and Wake Characteristics of the Small Ducted Fan for VTOL UAV (수직 이착륙 무인기용 소형 덕티드팬의 공력성능 및 후류특성에 관한 실험적 연구)

  • Shin, Soo-Hee;Lee, Seung-Hun;Kim, Yang-Won;Cho, Tae-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.1
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    • pp.1-12
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    • 2022
  • Wind tunnel test for a small scale electric ducted fan with a 104mm diameter was conducted to analyze the aerodynamic characteristics when it was used as a propulsion system of tilt-propeller UAV. Experimental conditions were derived from flight conditions of a sub-scaled OPPAV. Forces and moments of the ducted fan model were measured by a 6-axis balance and 3-dimensional wake vectors which could induce an aerodynamic influence in the vehicle were measured by 5-hole probes. Thrust and torque on hover and cruise conditions were measured and analyzed to drive out the operating conditions when it was applied in the sub-scaled OPPAV. On transition conditions, thrust keep its value with tilt angle variation below 40° and increase after that. But, sideforce increase constantly until 75°. The maximum axial velocity in the wake on hover and cruise conditions was around 60m/s and tangential velocity was around 12m/s. The position of the maximum axial velocity and vortex center move off the fan rotation center line as the tilt angle increases.

Study for Failure Examples Including with Gas filter Clogging of Emergency Cutting Valve, Assemblying Part Damage of Solenoid Valve, Contact Damage of LPG Switch Connector Fin in a LPG Car (LPG 자동차의 긴급차단밸브 기상필터막힘, 솔레노이드밸브 조립부손상, LPG 스위치 커넥터 핀 접촉불량에 관련된 고장사례 연구)

  • Lee, IL Kwon;Kook, Chang Ho;Ham, Sung Hoon;Kim, Jee Hyun;Kim, Sung Mo;Jung, Dong Hwa;You, Chang Bae;Moon, Hak Hoon;Lee, Jeong Ho
    • Journal of the Korean Institute of Gas
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    • v.26 no.1
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    • pp.1-6
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    • 2022
  • This paper is a purpose to study and analyze the engine starting failure examples for LPG car. The first example, the researcher verified the phenomenon that didn't supply the fuel because of filter clogging by fine alien substance in the gas valve line when he inspected the emergency cutting valve. The second example, there was no the influence of gas leakage when the solenoid operated at first. But the damage part of solenoid assemblying face wad downed a durability according to running a valve. Eventually, the researcher checked on the phenomenon of engine stopping by no gas feeding in solenoid because of leaking of gas. The third example, the researcher sought that the wiring sheaths of connector fin between EGR 10A fuse and LPG switch verified the burn-out phenomenon due to the bad contacting as tension damage produced the overheating. Therefore, the manager of a car has to do pre-inspection no producing electric failure and he must maintain his car with optimum condition.

Sentiment Analysis and Issue Mining on All-Solid-State Battery Using Social Media Data (소셜미디어 분석을 통한 전고체 배터리 감성분석과 이슈 탐색)

  • Lee, Ji Yeon;Lee, Byeong-Hee
    • The Journal of the Korea Contents Association
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    • v.22 no.10
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    • pp.11-21
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    • 2022
  • All-solid-state batteries are one of the promising candidates for next-generation batteries and are drawing attention as a key component that will lead the future electric vehicle industry. This study analyzes 10,280 comments on Reddit, which is a global social media, in order to identify policy issues and public interest related to all-solid-state batteries from 2016 to 2021. Text mining such as frequency analysis, association rule analysis, and topic modeling, and sentiment analysis are applied to the collected global data to grasp global trends, compare them with the South Korean government's all-solid-state battery development strategy, and suggest policy directions for its national research and development. As a result, the overall sentiment toward all-solid-state battery issues was positive with 50.5% positive and 39.5% negative comments. In addition, as a result of analyzing detailed emotions, it was found that the public had trust and expectation for all-solid-state batteries. However, feelings of concern about unresolved problems coexisted. This study has an academic and practical contribution in that it presented a text mining analysis method for deriving key issues related to all-solid-state batteries, and a more comprehensive trend analysis by employing both a top-down approach based on government policy analysis and a bottom-up approach that analyzes public perception.