• Journal of Ocean Engineering and Technology
• /
• v.33 no.2
• /
• pp.196-202
• /
• 2019

In this study, the excessive noise and vibration phenomena of a high-speed Ro/Ro passenger ship were analyzed, and a countermeasure was taken based on them. This ship was granted a comfort class notation by the classification society, which was COMFORT-VIBRATION-II and COMFORT-NOISE-CREW-II. However, unfortunately, excessive noise and vibration in the aft part of the ship were delivered from the twin shaft propellers, and therefore the Class Requirement was not satisfied before delivery. In order to obtain the class notation, all of the concerned parties came to an agreement to reduce the noise and vibration level during operation after delivery because a seasonal ferry service was already scheduled and the cabin was fully booked. The root cause of the massive amount of noise and vibration was mainly the propeller-induced excitation pulse and beating that occurred from the mismatch of the rotating speeds of the two shaft lines. A 1st order vibrating force and beating phenomena existed in the propeller. Thus, a reduction of the excitation force, elimination of the beating phenomena, and decrease of the noise level at the aft area cabins and public spaces were required. In addition, structural reinforcements were conducted using pillars and additional girders at the aft part of the decks.

• Wind and Structures
• /
• v.24 no.5
• /
• pp.405-430
• /
• 2017

The aerodynamic characteristics of vehicles are critical to assess vehicle safety and passenger comfort for vehicles running on long span bridges in a windy environment. However, in previous wind-vehicle-bridge (WVB) system analysis, the aerodynamic interference between the vehicle and the bridge was seldom considered, which will result in changing aerodynamic coefficients. In this study, the aerodynamic coefficients of a high-sided truck on the ground (ground case) and a typical bridge deck (bridge deck case) are determined in a wind tunnel. The effects of existent structures including the bridge deck and bridge accessories on the high-sided vehicle's aerodynamic characteristics are investigated. A three-dimensional analytical framework of a fully coupled WVB system is then established based on the finite element method. By inputting the aerodynamic coefficients of both cases into the WVB system separately, the vehicle safety and passenger comfort are assessed, and the critical accidental wind speed for the truck on the bridge in a windy environment is derived. The differences in the bridge response between the windward case and the leeward case are also compared. The results show that the bridge deck and the accessories play a positive role in ensuring vehicle safety and improving passenger comfort, and the influence of aerodynamic interference on the response of the bridge is weak.

• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.83-94
• /
• 1999

This study is about design of vehicle for air tightness to pressure waves of high speed train. When the train runs to high speed over 300km/h, the comfort of passenger come down due to difference pressure between inside and outside of passenger room. The car-body was carried out the design of air-tightness, and the analysis of inside pressure of vehicle in tunnel by TG_TUN of ALSTOM Co. The result of analysis should be used the design of air pressurized system and car-body of G7 high speed train project.

• Proceedings of the KSR Conference
• /
• 2002.10b
• /
• pp.954-961
• /
• 2002

Ventilation system on passenger rooms should be designed for the health and comfort of the passengers. One of the main aim is to create an acceptable thermal environment without draught problems. The draught sensation increases when the air temperature decreases and the air velocity increases. Airflow in passenger rooms is turbulent. Lateral temperature and humidity gradients in the electric rolling stock have been studied. And, the difference in the mean temperatures measured at 0.7, 0.9, 1.2, 1.7 m above the floor. It has been found that temperature with large fluctuations caused more draught complains.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.1327-1334
• /
• 2011

subway has became citizen's feet which can transport over 24 million people since the era of high oil price started. Because the request of passengers for more comfortable thermal comfort is drastically increasing, the importance of comfortable environment in the passenger car is more stressed. This paper suggests an indicator whether railroad car is fitted with suitable cooling and heating equipment by applying the international climatic testing method, UIC 553, 553-1. Specified ambient temperature, humidity, solar irradiation condition, as well as extreme outside condition, can be achieved by using an environmental chamber. The change temperature and humidity in the passenger space can be monitored to judge if the passenger room is nicely air-conditioned.

• Journal of the Korean Society of Visualization
• /
• v.8 no.2
• /
• pp.40-44
• /
• 2010

Thermal comfort inside a passenger car has been receiving large attention in automobile industries. Especially, the performance of windshield defroster is important in the design of a car to ensure passenger comport and safety. Thereby, better understanding on the ventilation flow along the vehicle windshield is essential to evaluate the performance of windshield defroster. However, most previous studies dealt with the defrost flow using CFD (computational fluid dynamics) calculations or scale-down model experiments. In this study, a real commercial automobile was used to investigate the flow discharged from the vehicle defroster and the ventilation flow along the windshield using a PIV velocity field measurement technique. The experimental data would be useful to understand the flow characteristics in detail and also can be used to validate numerical predictions.

• Journal of the Society of Naval Architects of Korea
• /
• v.52 no.4
• /
• pp.290-297
• /
• 2015

This research is focusing on the added resistance and seakeeping ability of the designed passenger ship with gooseneck bulb(Designed hull) which provide the improvement of resistance performance under calm water condition. By comparing the added resistances and seakeeping abilities of the reference hull and the designed hull form with gooseneck bulb, it is confirmed that there is little difference in the operational comfort and the reduction of ship speed. As a result, the applied gooseneck bulb in this study is verified for the applicability to medium-sized passenger ships with a good resistance performance.

• International Journal of Aerospace System Engineering
• /
• v.2 no.1
• /
• pp.31-37
• /
• 2015

Passenger plane flying motion graphics is very important for route, control of the flight altitude and passenger safety. For all that, it is quite useful for route away from the disruptive influences such as vibrations caused by storms or turbulence during the flight and in processes such as re-arrest of the specified route. Therefore, the response time against the adverse effects of the shape and the system is so necessary for both safety and comfort. In this study motion and route graphics were obtained under the control of an airliner C # interface with the program. In this way, graphics were obtained in solving the equations of motion in short time and design time was shortened.

• IE interfaces
• /
• v.14 no.2
• /
• pp.210-217
• /
• 2001

Because passenger seat is one of the most important parts in the determination of passengers' satisfaction for train, it is absolutely important to design the passenger seat so that train passengers can satisfy. So, in the seat design it is necessary to consider passengers' characteristics, requirements, and dissatisfactions. However, passengers' dissatisfactions for the seat of Mugunghwa-ho train have been often raised through various routes. It is necessary to resolve their dissatisfactions to provide comfortable trip to passengers. So, we designed a new seat of Mugunghwa-ho train that resolved passengers' dissatisfactions. Our focusing design parts were the seat pan and the backrest of passenger seat. We investigated passengers' dissatisfactions for the seat of Mugunghwa-ho train through various methods and the human factors design guidelines through literature survey. We designed a new seat on the basis of investigated results. For newly designed seat, we evaluated comfort and sensible satisfaction in comparison with the existing seat. An experimental method and subjective methods were used in this evaluation. In all aspects, the new seat was superior to the existing.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.3 no.5
• /
• pp.100-110
• /
• 1995

The human subject perception response according to vertical vibration and pitching was analyzed with a five degree of freedom model. The vehicle dynamic system with the delayed colored noise excitation and the passenger perception response was arranged as an integrated viration system and could be analyzed simultaneously for seven different combination of vehicle suspension. ISO2631 and BS6841 was adapted for analyzing the passenger perception reponse. Simulation results shows that passenger feel relatively less discomfort due to pitching compared to vertical vibration and road type was not necessary to be considered as a design parameter in view of comfort analysis.