• Title/Summary/Keyword: Simulated Flight Test

Search Result 52, Processing Time 0.032 seconds

Numerical simulation of 3-D probabilistic trajectory of plate-type wind-borne debris

  • Huang, Peng;Wang, Feng;Fu, Anmin;Gu, Ming
    • Wind and Structures
    • /
    • v.22 no.1
    • /
    • pp.17-41
    • /
    • 2016
  • To address the uncertainty of the flight trajectories caused by the turbulence and gustiness of the wind field over the roof and in the wake of a building, a 3-D probabilistic trajectory model of flat-type wind-borne debris is developed in this study. The core of this methodology is a 6 degree-of-freedom deterministic model, derived from the governing equations of motion of the debris, and a Monte Carlo simulation engine used to account for the uncertainty resulting from vertical and lateral gust wind velocity components. The influence of several parameters, including initial wind speed, time step, gust sampling frequency, number of Monte Carlo simulations, and the extreme gust factor, on the accuracy of the proposed model is examined. For the purpose of validation and calibration, the simulated results from the 3-D probabilistic trajectory model are compared against the available wind tunnel test data. Results show that the maximum relative error between the simulated and wind tunnel test results of the average longitudinal position is about 20%, implying that the probabilistic model provides a reliable and effective means to predict the 3-D flight of the plate-type wind-borne debris.

The Quantitative Analysis of Alternative-Decision in Missile Test: Focusing on Selecting a Foreign Test Site through Data Envelopment Analysis (미사일 시험을 위한 대안결정의 정량적 분석: 자료포락분석을 이용한 국외 시험장 선정을 중심으로)

  • Han, Seung Jo
    • Convergence Security Journal
    • /
    • v.20 no.4
    • /
    • pp.3-12
    • /
    • 2020
  • Although the related regulations or guidelines are not specified in the defense weapon system R&D process, R&D authorities frequently encounter problems that require rational decision-making. If the rational process is not applied in the matter of alternative choice, the project could be disrupted, which can result in longer project periods or more resource provision. In particular, a variety of decision-making methods are needed for test&evaluation of missile R&D. The issue of selecting a test site is one of the representative decision-making problems. If it is needed to determine the priority of multiple sites, Delphi Method and Analytic Hierarchy Process(AHP) will be applied. However, if the input of cost is to be considered, Data Envelopment Analysis(DEA) is more valuable to solve the problem. This paper proposes a solution to handle quantitatively various decision-making problems that can occur in missile flight test, and shows how DEA is applied through a simulated case study of selecting a foreign test site.

Gasdynamic Adjustment at Modeling of Flight Conditions Appropriate M=6

  • 우관제
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2000.04a
    • /
    • pp.8-8
    • /
    • 2000
  • In this paper are presented main power and gasdynamic characteristics of C-l6VK hypersonic test cell of Research Test Center of CIAM. Gasdynamic adjustment of the C-l6VK test cell was carried out with the working section constructed on scheme of Ramjet/scramjet test in free stream. Gasdynamic adjustment was conducted stage by stage in tile following sequence. First, check and preparation of all technical systems and checking measuring system. Than determination of the characteristics of test cell on cold (without the heating of air at entrance) regime and determination of the characteristics of test cell on regimes with the heating of air. Finally determination of tile characteristics of test cell with the loading of the working part by object. On tile final stage of gasdynamic adjustment two experiments with tile axisymmetric Scramjet model loaded into the working part of test cell were conducted. The first experiment was conducted with the purpose of determination of flow parameters with the object leaded into the working part and verification of experiment cyclogram. The second experiment was conducted with injection of hydrogen into the combustion chamber of object, that is tile conditions on test cell simulated Scramjet flight Mach number M = 6. Such methodology of gasdynamic adjustment allows to determine influence of experimental object on flow parameters in the working part at different conditions of experiment (with the burning in combustion chamber of object and without the homing), and also to compare flow characteristics in the object duct.

  • PDF

Collision Avoidance Maneuver Simulation of Tilt Rotor Unmanned Aerial Vehicle (틸트로터 무인기의 충돌회피기동 모사)

  • Hwang, Soo-Jung;Lee, Myeong-Kyu;Oh, Soo-Hun
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.15 no.3
    • /
    • pp.33-45
    • /
    • 2007
  • The collision avoidance maneuver flight simulation for tilt rotor unmanned aerial vehicle was performed by time-accurate numerical integration method based on wind tunnel test data. Five representative collision avoidance maneuvers were simulated under constraints of aerodynamic stall, propulsion power, structural load, and control actuator capability. The collision avoidance performances of the maneuvers were compared by the computed collision avoidance times. The sensitivities of initial flight speed and collision zone shape on the collision avoidance time were investigated. From these results, it was found that the moderate pull-up turn maneuver defined using moderate pitch and maximum roll controls within simulation constraints is the most robust and efficient collision avoidance maneuver under the various flight speeds and collision object shapes in the tilt rotor UAV applications.

  • PDF

Reliability of Measurement Estimation in Altitude Engine Test (엔진 고도 시험의 측정 신뢰성 평가)

  • Lee, Jin-Kun;Yang, In-Young;Yang, Soo-Seok;Kwak, Jae-Su
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.14 no.3
    • /
    • pp.1-6
    • /
    • 2006
  • The altitude engine test is a sort of engine performance tests carried out to measure the performance of a engine at the simulated altitude and flight speed environments prior to that at the flight test. During the performance test of a engine, various values such as pressures and temperatures at different positions, air flow rate, fuel flow rate, and the load by thrust are measured. These measured values are used to derive the representative performance values such as the net thrust and the specific fuel consumption through a momentum equation. Hence each of the measured values has certain effects on the total uncertainty of the performance values. In this paper, the combined standard uncertainties of the performance variables at the engine test were estimated by the uncertainty analysis of the measurement values and the repeatability and reproducibility of the altitude test measurement were assessed by the analysis of variation on the repeated test data with different operator groups.

  • PDF

PREDICTION OF AIRCRAFT FLOW FIELD EFFECT BY DIRECT CALCULATION OF INCREMENTAL COEFFICIENTS (증가 계수의 직접 계산법을 이용한 항공기 유동장 효과의 예측)

  • Kim, Eu-Gene;Kwon, Jang-Hyuk
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2006.10a
    • /
    • pp.41-46
    • /
    • 2006
  • When new weapons are introduced, the target points estimation is one of the important objectives in the flight test as well as the safe separation. The prediction methods help to design the flight test schedule. However, the incremental aerodynamic coefficients in the aircraft flow field so-called BSE are difficult to predict. Generally, the semiempirical methods such as the grid methods, IFM and Flow TGP using database are used for estimation of BSE. However, these methods are quasi-steady methods using static aerodynamic loads. Nowadays the time-accurate CFD method is often used to predict the store separation event. In the current process, the incremental aerodynamic coefficients in BSE regime are calculated directly, and the elimination of delta coefficients is checked simultaneously. This stage can be used for the initial condition of Flow TGP with freestream database. Two dimensional supersonic and subsonic store separation problems have been simulated and incremental coefficients are calculated. The results show the time when the store gets out of BSE region.

  • PDF

Missile Aerodynamic Structure and Parameter Identification (미사일의 동력학적 구조 및 계수 추정법)

  • Jang-Gyu Lee
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.32 no.10
    • /
    • pp.367-375
    • /
    • 1983
  • An extended Kalman filter (EKF) algorithm for estimating aerodynamic parameters from missile flight data is evaluated using simulated test data. The algorithm includes a general purpose 6-DOF missile airframe suitable for representing a variety of missile configurations. The EKF is demonstrated to be well suited as a postflight analysis tool for extracting large numbers of airframe parameters from flight test measurements. A structure identification algorithm is evaluated using synthetic measurement data. This algorithm used in conjunction with the parameter identification algorithm, can select that model from a family of candidate models which most likely produced the synthetic measurement data.

  • PDF

The Design of a Battery Power System and Its Performance Evaluation on the Ground for Vertical Takeoff and Landing Drones (수직 이착륙 무인기용 배터리 전력 시스템 설계 및 지상 시험 평가)

  • Gang, Byeong Gyu
    • Journal of Aerospace System Engineering
    • /
    • v.15 no.5
    • /
    • pp.43-49
    • /
    • 2021
  • This research shows how is designed, and its performance is evaluated on the ground for the VTOL drone before the flight test initiates. The targeted drone weight is approximately 45 kg including battery packs, and 4 motors are utilized to produce thrust and control directions. 30 min flight schedules were simulated to estimate the total power consumptions which result in 2.4 kWh. Then, two packs of 13-cells lithium-polymer battery with operating voltage ranging between 54 V and 44 V with up to 4 C-rate were fabricated to safely operate a VTOL drone. Moreover, the battery management system was installed to prevent over and under-voltage and over-current while running a battery system. To finally verify battery's performance, we conducted a ground evaluation for discharging battery tests at -10 ℃, 25 ℃ and 40 ℃, resulting in satisfying simulated power consumption conditions for flight schedules.

The Development of The Simulation Environment for Operating a Simultaneous Man/Unmanned Aerial Vehicle Teaming (유/무인 항공기 복합운용체계 검증을 위한 시뮬레이션 환경 구축)

  • Gang, Byeong Gyu;Park, Minsu;Choi, Eunju
    • Journal of Aerospace System Engineering
    • /
    • v.13 no.6
    • /
    • pp.36-42
    • /
    • 2019
  • This research illustrates how the simulation environment for operating the simultaneous man/unmanned aerial vehicle teaming is constructed. X-Plane program, HILS for the ducted fan aircraft (unmanned) and CTLS (manned aircraft) with communication devices are interfaced to simulate the basic co-operational flight. The X-plane and HILS can allow operators to experience the maned and unmanned aircraft operation in the airspace on the ground in turn they can perform various simulated missions in advance before the actual flight. For the test purpose, the data link between man/unmanned aircraft and ground control station is examined using C Band and UHF radio channels by the manned aircraft.

Aerodynamic Heating Analysis and Flight Test of KSR-III Rocket (KSR-III 공력가열 해석 및 비행시험)

  • Kim, Seong-Lyong;Lee, Jun-Ho;Kim, In-Sun;Cho, Kwang-Rae
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.32 no.8
    • /
    • pp.54-63
    • /
    • 2004
  • The inner surface temperatures of the KSR-III Sounding Rocket launched at 29th November 2002 were measured in the flight test, and the aerodynamic heating rate and outer surface temperature were calculated. The used program is the MINIVER code, which calculate the boundary layer equation based on the theoretical analysis, and its calculation is simulated on the flight time histories. The analysis considered the inner surface heat transfer with one dimensional solid heat conduction. The results showed that the major interior heat transfer is the radiation heat transfer, and the maximum outer surface temperature due to aerodynamic heating reached to 223C at fin and the maximum heating rate is about 133kW/m2 at nose cap. The whole analysis proved that the surface temperature remained below the allowable temperature, and the KSR-III thermal design satisfies the thermal environmental conditions.