Estimation of the Buffet Limited Altitude for a Typical Commercial Jet Aircraft

2016 ◽  
Vol 2 (4) ◽  
Author(s):  
Remya Varghese ◽  
Manu Jayakumar
Keyword(s):  
High Altitude ◽  
Air Temperature ◽  
Research Work ◽  
Load Factor ◽  
Wide Scope ◽  
Bank Angle ◽  
Fixed Weight ◽  
Main Motive ◽  
Mathematical Equations ◽  
Day To Day Operations

The estimation of Buffet limit altitude is highly pertinent while dealing with high altitude operations of commercial jet airplanes. Since buffet limitation is an important factor in deciding the airplane performance, the estimation of the same is highly recommended for day to day operations. In the research work conducted, the buffet restriction is considered by considering a load factor of 1.3 associated with 390 bank angle. The study is conducted under ISA, ISA+15 conditions for the airplane with fixed weight at the top of the climb segment. The main motive is to analyze the variation of 1.3g buffet limited altitude when the outside air temperature turns hotter and its dependence on airplane weight. The mathematical equations used for calculating the variation of lift with altitude and ISA conditions are stated in the paper. The results are well illustrated with the aid of graphs and plots. The research offers a wide scope on the analysis of altitude limitations for commercial jet airplanes and a sharp orientation towards further studies in the respective regime.

Labview-Based Automatic Four-Axis Positioning Control Air Temperature and Wind Speed Detection Platform for Drying Oven

2013 ◽  
Vol 718-720 ◽  
pp. 1547-1553 ◽  
Author(s):  
Neng Sheng Bao ◽  
Shi Liang Fei ◽  
Xue Jia Huang ◽  
Tie Quan Liu ◽  
Jin Huang
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Software Design ◽  
Research Work ◽  
Three Dimensional ◽  
Theoretical Research ◽  
Positioning Control ◽  
Processing Data ◽  
Cartesian Coordinate ◽  
Data Acquisition And Processing

The design of domestic drying oven lacked theoretical basis and methods, especially a tool supporting experiments and verifying the results of theoretical research. This paper developed a platform, which can be used to automatically detect multi-point air temperature and wind speed from drying oven nozzle of printing and coating machines. The hardware design of platform achieves a four-axis positioning function by adopt a three-dimensional Cartesian coordinate robot and an additional servo motor. The LabVIEW-based software design of platform achieves many functions, including multi-axis positioning control, data acquisition and processing, data interface and operation interface. This platform contributes to research work for drying oven.

Total air temperature anomalies as a metric for detecting high-altitude ice crystal events: Development of a failure indicator heuristic

2019 ◽  
Vol 105 ◽  
pp. 982-1005
Author(s):  
Álvaro Rodríguez-Sanz ◽  
Rosa Arnaldo Valdés ◽  
Fernando Gómez Comendador ◽  
Eduardo Sánchez Ayra ◽  
Javier Cano Cancela
Keyword(s):  
High Altitude ◽  
Air Temperature ◽  
Ice Crystal ◽  
Temperature Anomalies ◽  
Air Temperature Anomalies

scholarly journals User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation

2020 ◽  
Vol 12 (22) ◽  
pp. 9672
Author(s):  
Mamdooh Alwetaishi ◽  
Ashraf Balabel ◽  
Ahmed Abdelhafiz ◽  
Usama Issa ◽  
Ibrahim Sharaky ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
High Altitude ◽  
Air Temperature ◽  
Thermal Performance ◽  
Indoor Air ◽  
Computer Modelling ◽  
Evaporative Cooling ◽  
Comfort Level ◽  
Thermal Mass ◽  
The Impact

The study investigated the level of thermal comfort in historical buildings located at a relatively high altitude in the Arabian Desert of Saudi Arabia. The study focused on the impact of the use of thermal mass and orientation on the level of thermal performance at Shubra and Boqri Palaces. Qualitative and quantitative analyses were used in this study, including a questionnaire interview with architecture experts living at the relatively high altitude of Taif city, to obtain data and information from local experts. The computer software TAS EDSL was used along with on-site equipment, such as thermal imaging cameras and data loggers, to observe the physical conditions of the building in terms of its thermal performance. The study revealed that the experts’ age and years of experience were important aspects while collecting data from them during the survey. The use of thermal mass had a slight impact on the indoor air temperature as well as the energy consumption, but it helped in providing thermal comfort. Use of ventilation can improve thermal comfort level. Evaporative cooling technique has a considerable impact on reducing indoor air temperature with 4 °C drop, improving the thermal comfort sensation level. The novelty of this work is that, it links the outcomes of qualitative results of experts with field monitoring as well as computer modelling. This can contribute as method to accurately collect data in similar case studies.

Regionalization of precipitation and air temperature over high-altitude catchments – learning from outliers

2010 ◽  
Vol 55 (6) ◽  
pp. 928-940 ◽  
Author(s):  
Audrey Valéry ◽  
Vazken Andréassian ◽  
Charles Perrin
Keyword(s):  
High Altitude ◽  
Air Temperature

Increasing Altitude and the Optokinetic Cervical Reflex

2021 ◽  
Vol 92 (5) ◽  
pp. 319-325
Author(s):  
Matthew A. Stewart ◽  
Sravan Pingali ◽  
David G. Newman
Keyword(s):  
High Altitude ◽  
Opposite Direction ◽  
Spatial Orientation ◽  
Visual Cues ◽  
Head Tilt ◽  
Flight Simulator ◽  
Visual Environment ◽  
Bank Angle ◽  
Environment Changes ◽  
Post Hoc

INTRODUCTION: When an aircraft banks pilots will reflexively tilt their heads in the opposite direction, known as the optokinetic cervical reflex (OKCR). This is elicited by the appearance of the horizon and is an attempt to keep the moving horizon stable on the pilots retina to help maintain spatial orientation. The appearance of the horizon and the visual environment changes at higher altitudes and there is little research studying the effects of this. Our hypothesis was that increasing altitude would alter the visual cues present and decrease the OKCR.METHODS: There were 16 subjects who flew two flights in a flight simulator while their head tilt, aircraft altitude, and angle of aircraft bank were recorded. The flights were at an altitude of under 1500 ft above ground and above 15,000 ft above ground.RESULTS: Aircraft bank caused head tilt in the opposite direction at both altitudes. A two-way ANOVA with Bonferroni post hoc tests showed that 86% of aircraft bank angles from 0 to 90 in either direction had a head tilt that was statistically significantly smaller at high altitude.DISCUSSION: This study shows that there appears to be a difference between the OKCR at low and high altitude. Pilots at higher altitude seem to exhibit a smaller head tilt for the same aircraft bank angle. More research is required to fully understand why there is a decrease in the OKCR at high altitude, as well as the actual consequences of the decreased reflex on pilot orientation.Stewart MA, Pingali S, Newman DG. Increasing altitude and the optokinetic cervical reflex. Aerosp Med Hum Perform. 2021; 92(5):319325.

scholarly journals Seasonal thermal regime and climatic trends in lakes of the Tibetan highlands

2017 ◽  
Vol 21 (4) ◽  
pp. 1895-1909 ◽  
Author(s):  
Georgiy Kirillin ◽  
Lijuan Wen ◽  
Tom Shatwell
Keyword(s):  
Tibetan Plateau ◽  
High Altitude ◽  
Air Temperature ◽  
Thermal Regime ◽  
Mixed Boundary ◽  
Reanalysis Data ◽  
Shortwave Radiation ◽  
The Tibetan Plateau ◽  
Seasonal Temperature ◽  
High Altitude Lakes

Abstract. The hydrology of the lake-rich Tibetan Plateau is important for the global climate, yet little is known about the thermal regime of Tibetan lakes due to scant data. We (i) investigated the characteristic seasonal temperature patterns and recent trends in the thermal and stratification regimes of lakes on the Tibetan Plateau and (ii) tested the performance of the one-dimensional lake parameterization scheme FLake for the Tibetan lake system. For this purpose, we combined 3 years of in situ lake temperature measurements, several decades of satellite observations, and the global reanalysis data. We chose the two largest freshwater Tibetan lakes, Ngoring and Gyaring, as study sites. The lake model FLake faithfully reproduced the specific features of the high-altitude lakes and was subsequently applied to reconstruct the vertically resolved heat transport in both lakes during the last 4 decades. The model suggested that Ngoring and Gyaring were ice-covered for about 6 months and stratified in summer for about 4 months per year with a short spring overturn and a longer autumn overturn. In summer the surface mixed boundary layer extended to 6–8 m of depth and was about 20 % shallower in the more turbid Gyaring. The thermal regime of the transparent Ngoring responded more strongly to atmospheric forcing than Gyaring, where the higher turbidity damped the response. According to the reanalysis data, air temperatures and humidity have increased, whereas solar radiation has decreased, since the 1970s. Surprisingly, the modeled mean lake temperatures did not change, nor did the phenology of the ice cover or stratification. Lake surface temperatures in summer increased only marginally. The reason is that the increase in air temperature was offset by the decrease in radiation, probably due to increasing humidity. This study demonstrates that air temperature trends are not directly coupled to lake temperatures and underscores the importance of shortwave radiation for the thermal regime of high-altitude lakes.

Air temperature anomalies of summer 2010 measured at the high-altitude meteorological mast in Obninsk

2012 ◽  
Vol 37 (4) ◽  
pp. 235-239
Author(s):  
M. A. Novitskii ◽  
L. K. Kulizhnikova ◽  
M. K. Matskevich ◽  
N. F. Mazurin
Keyword(s):  
High Altitude ◽  
Air Temperature ◽  
Temperature Anomalies ◽  
Air Temperature Anomalies

Aircraft Dynamics for Symmetric and Asymmetric V-Shape Morphing Wings

2008 ◽  
Author(s):  
Edgar Cuji ◽  
Ephrahim Garcia
Keyword(s):  
Load Factor ◽  
Performance Measurements ◽  
Bank Angle ◽  
Horizontal Section ◽  
Moment Coefficient ◽  
Aerodynamic Model ◽  
Out Of Plane ◽  
Flap Deflection ◽  
Turning Radius ◽  
Aircraft Application

This paper will present the effect of the aircraft turning dynamics for symmetric and asymmetric V-shape changing wings. The aerodynamic forces will be calculated using a 3D aerodynamic model developed that utilizes a modern adaptation of Prandtl’s lifting-line method which can be used for wings of arbitrary camber, sweep and dihedral. The method will be applied to analyze symmetric and asymmetric V-shaped wing configuration of interest for morphing aircraft application. The V-shaped wing has two sections, an out-of-plane dihedral section and a horizontal section. A study of the lift characteristics for symmetric and asymmetric with and without flap deflection will be presented. An investigation as to how the partial dihedral will affect the dynamics of the vehicle, in turning, for wings with asymmetric flap deflection is performed. An comparison of the different turning performance measurements, turning radius, bank angle, load factor, turning rate and roll moment coefficient will be presented.

scholarly journals Effects of energy band structure on gallium arsenide based MOSFET

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Wut Hmone Kyaw ◽  
May Nwe Myint Aye
Keyword(s):  
Gallium Arsenide ◽  
Research Work ◽  
Band Gap Energy ◽  
Semiconductor Material ◽  
Oxide Semiconductor ◽  
Matlab Simulation ◽  
Group Iii ◽  
Mathematical Equations ◽  
Effect Transistor ◽  
Voltage Relationship

This research work is focused on material science and semiconductor engineering. It emphasized on the semiconductor material such as Gallium arsenide (GaAs). The Gallium arsenide semiconductor material was used as a group III-V compound for metal-oxide semiconductor field effect transistor (MOSFET) modeling.  The band-gap energy structures were analyzed by using material parameters such as Varshni parameters, temperature and doping concentrations. Then, an electrical characteristic was carried out depending on the current and voltage relationship. The current flowing in the device is associated with a gate voltage applied to the device. From this paper, the analysis of MOSFET modeling was investigated using mathematical equations and MATLAB simulation.

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