scholarly journals Sensitivity Analysis of Maximum Circulation of Wake Vortex Encountered by En-Route Aircraft

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 194
Author(s):  
Jose I. Rojas ◽  
Marc Melgosa ◽  
Xavier Prats
Keyword(s):  
Sensitivity Analysis ◽  
Dissipation Rate ◽  
Wake Vortex ◽  
Load Factor ◽  
Core Radius ◽  
Operational Conditions ◽  
Initial Strength ◽  
Efficient Test ◽  
Aircraft Data ◽  
Comprehensive Study

Wake vortex encounters (WVE) can pose significant hazard for en-route aircraft. We studied the sensitivity of wake vortex (WV) circulation and decay to aircraft mass, altitude, velocity, density, time of catastrophic wake demise event, eddy dissipation rate, wing span, span-wise load factor, and WV core radius. Then, a tool was developed to compute circulations of WV generated/encountered by aircraft en-route, while disregarding unrealistic operational conditions. A comprehensive study is presented for most aircraft in the Base of Aircraft Data version 4.1 for different masses, altitudes, speeds, and separation values between generator and follower aircraft. The maximum WV circulation corresponds to A380-861 as generator: 864 and 840 m2/s at horizontal separation of 3 and 5 NM, respectively. In cruise environment, these WV may descend 1000 ft in 2.6 min and 2000 ft in 6.2 min, while retaining 74% and 49% of their initial strength, respectively. The maximum circulation of WV encountered by aircraft at horizontal separation of 3 NM from an A380-861 is 593, 726, and 745 m2/s, at FL200, FL300, and FL395, respectively. At 5 NM, the circulations decrease down to 578, 708, and 726 m2/s. Our results allow reducing WVE simulations only to critical scenarios, and thus perform more efficient test programs for computing aircraft upsets en-route.

Study on the influence of linear and nonlinear distribution of crosswind on the motion of aircraft wake vortex

2021 ◽  
pp. 095441002098743
Author(s):  
Dong Li ◽  
Ziming Xu ◽  
Ke Zhang ◽  
Zeyu Zhang ◽  
Jinxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Dissipation Rate ◽  
Vortex Pair ◽  
Vertical Shear ◽  
Wake Vortex ◽  
Analysis Method ◽  
Velocity Magnitude ◽  
Aircraft Wake ◽  
Linear And Nonlinear ◽  
Nonlinear Distribution

Environmental crosswind can greatly affect the development of aircraft wake vortex pair. Previous numerical simulations and experiments have shown that the nonlinear vertical shear of the crosswind velocity can affect the dissipation rate of the aircraft wake vortex, causing each vortex of the vortex pair descent with different velocity magnitude, which will lead to the asymmetrical settlement and tilt of the wake vortex pair. Through numerical simulations, this article finds that uniform crosswind convection and linear vertical shear crosswind convection can also have an effect on the strength of the vortex. This effect is inversely proportional to the cube of the vortex spacing, so it is more intense on small separation vortex pair. In addition, the superposition of crosswind and vortex-induced velocities will lead to the asymmetrical pressure distribution around the vortex pair, which will also cause the tilt of the vortex pair. Furthermore, a new analysis method for wake vortex is proposed, which can be used to predict the vortex trajectory.

Sensitivity Analysis of Wake Vortex Parameters Measured by Doppler Lidar

2015 ◽  
Author(s):  
Takashi Misaka ◽  
Shigeru Obayashi ◽  
Anton Stephan ◽  
Frank N. Holzäpfel ◽  
Thomas Gerz
Keyword(s):  
Sensitivity Analysis ◽  
Wake Vortex ◽  
Doppler Lidar

A Discussion on recent research in air pollution - Plume rise estimates for electric generating stations

1969 ◽  
Vol 265 (1161) ◽  
pp. 221-243 ◽  
Keyword(s):  
Air Pollution ◽  
Pollution Control ◽  
Full Scale ◽  
Plume Rise ◽  
Air Pollution Control ◽  
Operational Conditions ◽  
The Public ◽  
Wide Range ◽  
Tennessee Valley ◽  
Comprehensive Study

The Tennessee Valley Authority, under sponsorship of the Public Health Service, National Air Pollution Control Administration, initiated a comprehensive study titled ‘ Full scale study of plume rise at large electric generating stations’ in 1963. The variability of plant sizes, stack heights, and stack configurations accommodated full scale assessment of plume rise over a wide range of meteorological and operational conditions.

Sensitivity analysis of a concentration fluctuation model to dissipation rate estimates

2012 ◽  
Vol 48 (1/2/3/4) ◽  
pp. 164 ◽  
Author(s):  
Andrea Amicarelli ◽  
Pietro Salizzoni ◽  
Giovanni Leuzzi ◽  
Paolo Monti ◽  
Lionel Soulhac ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Dissipation Rate ◽  
Concentration Fluctuation ◽  
Fluctuation Model

Simulation and sensitivity analysis of transport in asymmetric hollow fiber membrane permeators for air separation

RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86359-86370 ◽  
Author(s):  
Seyed Saeid Hosseini ◽  
Sara Najari ◽  
Prodip K. Kundu ◽  
Nicolas R. Tan ◽  
Seyed Mehrdad Roodashti
Keyword(s):  
Sensitivity Analysis ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Air Separation ◽  
Fiber Membrane ◽  
Operational Conditions ◽  
Separation Membrane

Development of advanced membranes requires deep insights about the process. Sensitivity analysis is performed to analyze the effects of module properties and process operational conditions on the performance of air separation membrane permeators.

scholarly journals Uncertainty and sensitivity analysis for reducing greenhouse gas emissions from wastewater treatment plants

2020 ◽  
Author(s):  
Giorgio Mannina ◽  
Alida Cosenza ◽  
Taise Ferreira Rebouças
Keyword(s):  
Mathematical Model ◽  
Sensitivity Analysis ◽  
Wastewater Treatment ◽  
Uncertainty Analysis ◽  
Total Nitrogen ◽  
Wastewater Treatment Plants ◽  
Ghg Emissions ◽  
Sensitivity Testing ◽  
N2o Formation ◽  
Operational Conditions

Abstract This paper presents the sensitivity and uncertainty analysis of a plant-wide mathematical model for wastewater treatment plants (WWTPs). The mathematical model assesses direct and indirect (due to the energy consumption) greenhouse gases (GHG) emissions from a WWTP employing a whole-plant approach. The model includes: i) the kinetic/mass-balance based model regarding nitrogen; ii) two-step nitrification process; iii) N2O formation both during nitrification and denitrification (as dissolved and off-gas concentration). Important model factors have been selected by using the Extended-Fourier Amplitude Sensitivity Testing (FAST) global sensitivity analysis method. A scenario analysis has been performed in order to evaluate the uncertainty related to all selected important model factors (scenario 1), important model factors related to the influent features (scenario 2) and important model factors related to the operational conditions (scenario 3). The main objective of this paper was to analyse the key factors and sources of uncertainty at a plant-wide scale influencing the most relevant model outputs: direct and indirect (DIR,CO2eq and IND,CO2eq, respectively), effluent quality index (EQI), chemical oxygen demand (COD) and total nitrogen (TN) effluent concentration (CODOUT and TNOUT, respectively). Sensitivity analysis shows that model factors related to the influent wastewater and primary effluent COD fractionation exhibit a significant impact on direct, indirect and EQI model factors. Uncertainty analysis reveals that outflow TNOUT has the highest uncertainty in terms of relative uncertainty band for scenario 1 and scenario 2. Therefore, uncertainty of influential model factors and influent fractionation factors has a relevant role on total nitrogen prediction. Results of the uncertainty analysis show that the uncertainty of model prediction decreases after fixing stoichiometric/kinetic model factors.

scholarly journals Parametric Sensitivity Analysis for the Industrial Case of O-Xylene Oxidation to Phthalic Anhydride in a Packed Bed Catalytic Reactor

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 626
Author(s):  
Santiago Zuluaga-Botero ◽  
Izabela Dobrosz-Gómez ◽  
Miguel-Ángel Gómez-García
Keyword(s):  
Sensitivity Analysis ◽  
Packed Bed ◽  
Stable Operation ◽  
Similar Reaction ◽  
Catalytic Reactor ◽  
Operational Conditions ◽  
Parametric Sensitivity ◽  
Rate Laws ◽  
Parametric Sensitivity Analysis ◽  
Operation Conditions

The operation of packed bed tubular reactors, for exothermic catalytic reactions, presents special challenges provoked by hotspot development. Their potential safety risk can be assessed using different mathematical methodologies, among them, the so-called parametric sensitivity analysis (PSA). This study deals with the identification of safe operational conditions (e.g., feed temperature conditions) for the catalytic oxidation of o-xylene. Three different reaction networks, with different degrees of complexity, were analyzed. Thus, the critical values of the operating parameters, allowing us to define run-away and stable operation conditions, were provided for different reactive configurations. The obtained results were compared with the data reported by various authors who used similar reaction rate laws. The purpose of the present study is to illustrate the peculiarities of the PSA and its application for the design, analysis, and operation of o-xylene multitubular catalytic reactor.

scholarly journals METODE REGRESI LINIER UNTUK PREDIKSI KEBUTUHAN ENERGI LISTRIK JANGKA PANJANG (STUDI KASUS PROVINSI LAMPUNG)

2014 ◽  
Vol 2 (2) ◽  
Author(s):  
M. Syafruddin ◽  
Lukmanul Hakim ◽  
Dikpride Despa
Keyword(s):  
Logical Consequence ◽  
Electricity Consumption ◽  
Load Factor ◽  
Electrical Load ◽  
Property Development ◽  
System Planning ◽  
Population Number ◽  
Electrical Load Forecasting ◽  
Consumption Prediction ◽  
Comprehensive Study

Abstrak— Meningkatnya pembangunan di Provinsi Lampung terutama di sektor perumahanbaik sederhana maupun rumah mewah yang membawa konsekuensi logis berupapeningkatan kebutuhan tenaga listrik. Sebuah studi komprehensif dalam rangkapenyedian tenaga listrik di Lampung menjadi kebutuhan yang mendesakdilakukan untuk membuat rencana operasi sistem  tenaga listrik. Salah satu faktoryang sangat menentukan dalam membuat rencana operasi sistem tenaga listriktersebut adalah prediksi beban listrik yang akan ditanggung oleh sistem tenagalistik yang bersangkutan. Penelitian ini bertujuan untuk memprediksi  kebutuhan energi  listrik  di  Provinsi  Lampung  hingga  Tahun 2030, diharapkan dapatdijadikan sebagai masukkan dalam melakukan perencanaan pembangunan sistemtenaga listrik. Prediksi kebutuhan energi listrik Lampung dibagi menjadi 4 sektoryaitu : sektor rumah tangga, bisnis, publik, dan industri. Proses perancanganprediksi kebutuhan energi listrik menggunakan 6 variabel dan dibagi menjadi 2 parameter,  yaitu: parameter ekonomi (produk domestik regional bruto, jumlahpenduduk, jumlah rumah tangga) dan parameter listrik (rasio elektrifikasi,  faktor beban,  losses). Dengan menggunakan metode regresi linier untuk memprediksivariabel-variabel di atas, diperoleh hasil prediksi daya listrik tersambung totalpada tahun 2028 sebesar 2.841,78 MVA (rata-rata pertumbuhannya sebesar 2,38 %), dan konsumsi energi listrik pada tahun 2023 sebesar 5.934,98 Gwh (rata-rata pertumbuhannya sebesar 3, 83 %).  Kata Kunci —regresi linier, konsumsi energi listrik, Provinsi Lampung. Abstract The Increasing of property development in  Lampung Province, especially in thehousing sector both simple and luxurious brings a logical consequence ofelectricity  demand.  A  comprehensive  study  for  electricity  provisioning  inLampung become requirement constrain. Electrical load forecasting is  one of theimportant factors is power system planning and making. Prediction of electricityconsumption there are for activity that need to  be predicted i.e.: households,businesses, public services, and industry. 6 variables include are considered grossregional domestic product, population, number of households, electrification ratio,load factor, losses are considered to be influencing the forecasting proses. Linearregression method was used to predict all variables. The result of total electricitypower connected prediction on 2028 is 2841.78 MVA (growth average at of 2,38%). And electricity consumption prediction on 2023 is 5934.98 Gwh (growthaverage at 3, 83%).  Keywords—linier regression, electricity consumption, Lampung Province.

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