• Journal of the Korean Society of Propulsion Engineers
• /
• v.13 no.6
• /
• pp.56-63
• /
• 2009

In this paper, we present technical survey results on propulsion systems for Personal Air Vehicles (PAV). Reciprocating engines are suitable for current PAVs because of their superior efficiency and price advantages, except they produce noise problems. Turbo-Shaft engines are suitable for VTOL PAVs because of high specific power and wide operating range even though they are expensive. However, fuel cells and batteries may replace conventional engines in the near future.

• Journal of Aerospace System Engineering
• /
• v.9 no.4
• /
• pp.55-61
• /
• 2015

In this study, we peformed optimal design of a composite skid landing gear, one of the solid spring shock absorbers, for light vertical takeoff and landing aircraft. Although a solid spring type has poor energy dissipation capability, it is commonly used for light aircraft where sink speeds are low and shock absorption is non-critical in terms of simplicity, low cost and weight reduction. In this paper, design parameters of solid spring such as sink speed, gear leg length, deflection and landing load factor were reviewed. In order to meet structural requirements such as deflection and strength, finally, we conducted optimal design of the composite skid landing gear for VTOL UAV using genetic algorithm and pattern search algorithm.

• Journal of the Korea Convergence Society
• /
• v.8 no.6
• /
• pp.219-226
• /
• 2017

As the UAV industry is getting matured, various types of UAVs have appeared in many application fields, including filming, reconnaissance, rescue, and etc. and it requires the quick hardware designs, particularly a battery pack, of the UAV. We developed the automatic battery pack design tool for the convenient battery pack configuration design of the hoverable type delivery UAV. With inputs, including current profile, voltage profile, various kinds of cell specifications, desired battery pack voltage, and etc. the automatic battery pack design tool calculates a pack having the minimum weight and the maximum capacity by combining either homogeneous cells or heterogeneous cells. Also, the tool could predict the capacity fading trend of the designed battery pack configuration.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.7
• /
• pp.26-31
• /
• 2003

In this paper, supersonic jets impinging on axisymmetric cone were investigated to obtain fundamental design data for jet deflector case of example being VTOL/STOL or rocket launch. It was of interest to study flow phenomena such as shock interactions and separation induced by shear layer. Experiments were conducted to obtain schlieren flow visualization and measurement of surface pressure. Numerical results are compared with the experimental result. The dominant feature of the flow is the shock pattern induced by the interaction between the cone shock and the barrel shock. This pattern can take a wide variety of forms depending on the structure of the free jet and strongly influences the form of the surface pressure distributions.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.6
• /
• pp.556-561
• /
• 2009

The UAV(Unmanned Aerial Vehicle) that is remotely operating in various and long flight environments must have a very reliable propulsion system. Precise fault diagnosis of the turbo shaft engine for the Smart UAV that has the vertical take-off, landing and forward flight behaviors can promote reliability and availability. This work proposes a new diagnostic method that can identify the faulted components from engine measuring parameter changes using Fuzzy Logic and quantify its faults from the identified fault pattern using Neural Network Algorithms. The proposed diagnostic method can detect not only single fault but also multiple faults.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.29 no.3
• /
• pp.52-65
• /
• 2021

A large amount of time and cost is consumed due to congestions caused by an increasing number of cars which results in a lot of emissions. To overcome these problems, a new electric vertical takeoff and landing (eVTOL) aircraft is being considered. Since vertical take off and landing without a separate runway is realized and electricity is used as a power source, it could solve the saturated ground traffic congestions without emissions. In this paper, the initial sizing was performed based on the Nexus 6HX of Belltextron which is a tilt-ducted fan type. In this study, the electric propulsion system that only uses battery was implemented instead of current Nexus 6HX hybrid electric propulsion. Aerodynamic analyses were performed using OpenVSP and XFLR5. Power-to-weight ratio, wing loading, estimated weight were calculated with these analyses.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.26 no.4
• /
• pp.122-128
• /
• 2018

A compound drone that combines a fixed wing and a rotary wing is an aircraft that can take off and landing vertically, and can increase flight time and fly faster with fixed wings. The compound drones are divided into many types depending on the method of adding the thrust vectoring or the lift fan and the position of the rotor. In this study, we designed and fabricated a composite drone with four V-TOL motors in a fixed-wing, and assigned missions to the aviation body, hence judged mission accuracy using the actual flight test. The design process and the mission evaluation process employed in this study can be utilized on the development of various unmanned aerial vehicle.

• Journal of IKEEE
• /
• v.23 no.1
• /
• pp.266-272
• /
• 2019

Multicopters have become more popular since they are advantageous in their ability to take off and land vertically. In order to guarantee the normal operations of such multicopters, the problem of fault detection and isolation is very important. In this paper, a new method for detecting and isolating an actuator fault of a hexacopter is proposed based on the analytical approach. The residual is newly defined using the angular velocities of actuators estimated by the mathematical model and an actuator fault is detected comparing the residuals to a threshold. And a fault is isolated combining a dynamic model and generated residuals when a fault is detected. The proposed method is a simple, but effective technique because it is based on mathematical model. The results of the computer simulation are also given to demonstrate the validity of the proposed algorithm in case of a single failure.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.4
• /
• pp.132-140
• /
• 2020

The development status was studied to predict the concept of how drone taxis would be presented in daily life. the results of the analysis on traffic effects of drone taxis showed that they would be an innovative transportation option that could reach a distance of 60km, which would typically take an hour by car, within twenty minutes. Moreover, the economic analysis of existing aircraft development was limited to production (development investment) of the input budget. However, since the drone taxi is a new transportation system, an overall traffic platform, such as its own terminals, would need to be established. So, the production inducement effect was analyzed by dividing input budget into three factors; production, infrastructure, and service. The results indicate this to be an innovative project expected to have an economic ripple effect and reach a total of 24 trillion won after an investment of 13 trillion won (production + infrastructure + service) in Korea from 2020 to 2040.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.4
• /
• pp.171-175
• /
• 2020

The present and future cities are expanding, and the noise and environmental pollution in cities are getting worse day by day, causing saturation of road and subway traffic. As a result, citizens are spending a great deal of time and money. The use of the sky as a measure to solve this problem has become a reality. However, airplanes that require airstrips and noisy helicopters are difficult to use in cities. As a solution, PAVs and UAMs that generate low noise and enable vertical takeoff and landing using electric energy, motor, hybrid, and hydrogen energy, are attracting attention, with its practicality being promoted in many countries. The development of urban environment and technology has led to the emergence of Personal Air Vehicle (PAV), Vertical Takeoff and Landing (eVTOL), and Urban Air Mobility (UAM) for shipping. Though currently at the level of testing, general commercialization of these air transport means is expected in the next five to fifteen years. This study suggests a plan on the application of human factors to the introduction of PAV and UAM.