scholarly journals An estimation method for the fuel burn and other performance characteristics of civil transport aircraft during cruise: part 2, determining the aircraft’s characteristic parameters

2020 ◽  
Vol 125 (1284) ◽  
pp. 296-340
Author(s):  
D.I.A. Poll ◽  
U. Schumann
Keyword(s):  
Estimation Method ◽  
Accurate Method ◽  
Characteristic Parameters ◽  
Transport Aircraft ◽  
The Public ◽  
Engine Thrust ◽  
Fuel Burn ◽  
Burn Rate ◽  
Drag Ratio ◽  
Independent Parameters

ABSTRACTA simple yet physically comprehensive and accurate method for the estimation of the cruise fuel burn rate of turbofan powered transport aircraft operating in a general atmosphere was developed in part 1. The method is built on previously published work showing that suitable normalisation reduces the governing relations to a set of near-universal curves. However, to apply the method to a specific aircraft, values must be assigned to six independent parameters and the more accurate these values are the more accurate the estimates will be. Unfortunately, some of these parameters rarely appear in the public domain. Consequently, a scheme for their estimation is developed herein using basic aerodynamic theory and data correlations. In addition, the basic method is extended to provide estimates for cruise lift-to-drag ratio, engine thrust and engine overall efficiency. This step requires the introduction of two more independent parameters, increasing the total number from six to eight. An error estimate and sensitivity analysis indicates that, in the aircraft’s normal operating range and using the present results, estimates of fuel burn rate are expected to be in error by no more than 5% in the majority of cases. Initial estimates of the characteristic parameters have been generated for 53 aircraft types and engine combinations and a table is provided.

scholarly journals An estimation method for the fuel burn and other performance characteristics of civil transport aircraft in the cruise. Part 1 fundamental quantities and governing relations for a general atmosphere

2020 ◽  
Vol 125 (1284) ◽  
pp. 257-295 ◽  
Author(s):  
D.I.A. Poll ◽  
U. Schumann
Keyword(s):  
Reynolds Number ◽  
Temperature Profile ◽  
Numerical Solutions ◽  
Estimation Method ◽  
Atmospheric Conditions ◽  
Absolute Minimum ◽  
Vertical Temperature Profile ◽  
Unit Distance ◽  
Transport Aircraft ◽  
Fuel Burn

AbstractThis paper is one of a series addressing the need for simple, yet accurate, methods for the estimation of cruise fuel burn and other important aircraft performance parameters. Here, a previously published, constant Reynolds number model for turbofan-powered, civil transport aircraft is extended to include Reynolds number effects. Provided the variation of temperature with pressure is known, the method is applicable to flight in any atmospheric conditions. For a given aircraft, cruising in a given atmosphere, there is a single Mach number and Flight Level pair, at which the fuel burn per unit distance travelled through the air has an absolute minimum value. Both these quantities depend upon the Reynolds number, which, in turn, depends upon the aircraft weight and the atmospheric vertical temperature profile. Simple, explicit expressions are developed for all parameters at the optimum condition. These are shown to be in close agreement with numerical solutions of the governing equations. It is found that typical operational mass and temperature profile variations can change cruise fuel burn rate by several percent. In the International Standard Atmosphere, when the speed and altitude deviate from their optimum values, the fuel burn penalty is reduced slightly relative to the constant Reynolds number case. By way of example, the method is used to estimate the minimum fuel, speed-versus-height trajectory for cruise in a realistic atmosphere.For each aircraft, cruise fuel burn is found to be governed by six independent parameters. All are constants. Two are simple, involving only size and weight, whereas four are complex and must be determined by either theoretical, or empirical, means. The estimation of these quantities will be considered in Part 2.

Screening of retired lithium-ion batteries using incremental capacity charging curve based residual capacity estimation method for facilitating sustainable circular lithium-ion battery system

2021 ◽  
pp. 1-16
Author(s):  
Honglei Li ◽  
Liang Cong ◽  
Huazheng Ma ◽  
Weiwei Liu ◽  
Yelin Deng ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Estimation Method ◽  
Lithium Ion ◽  
Capacity Fade ◽  
Characteristic Parameters ◽  
Capacity Estimation ◽  
Capacity Curve ◽  
Residual Capacity ◽  
Remaining Capacity ◽  
Incremental Capacity

Abstract The rapidly growing deployment of lithium-ion batteries in electric vehicles is associated with a great waste of natural resource and environmental pollution caused by manufacturing and disposal. Repurposing the retired lithium-ion batteries can extend their useful life, creating environmental and economic benefits. However, the residual capacity of retired lithium-ion batteries is unknown and can be drastically different owing to various working history and calendar life. The main objective of this paper is to develop a fast and accurate capacity estimation method to classify the retired batteries by the remaining capacity. The hybrid technique of adaptive genetic algorithm and back propagation neural network is developed to estimate battery remaining capacity using the training set comprised of the selected characteristic parameters of incremental capacity curve of battery charging. Also, the paper investigated the correlation between characteristic parameters with capacity fade. The results show that capacity estimation errors of the proposed neural network are within 3%. Peak intensity of the incremental capacity curve has strong correlation with capacity fade. The findings also show that the translation of peak of the incremental capacity curve is strongly related with internal resistance.

Thrust Nozzles for Supersonic Transport Aircraft

1964 ◽  
Vol 86 (2) ◽  
pp. 97-104 ◽  
Author(s):  
David Migdal ◽  
John J. Horgan
Keyword(s):  
External Flow ◽  
Operating Costs ◽  
Jet Engine ◽  
Transport Aircraft ◽  
Supersonic Transport ◽  
The Past ◽  
Engine Thrust ◽  
Performance Trends ◽  
Flow Effects ◽  
Plug Nozzles

Supersonic transports will require jet-engine thrust nozzles that are highly efficient from take-off to supersonic cruise in order to minimize the direct operating costs. Variable-area ejectors, plug nozzles, and modifications of these basic types have been tested extensively during the past several years. Performance trends for these nozzles are presented with the emphasis on external flow effects. A new ejector which utilizes aerodynamically actuated doors to admit external air into the ejector shroud is discussed.

Lift/Drag Ratios of Optimised Slewed Elliptic Wings at Supersonic Speeds

1961 ◽  
Vol 12 (3) ◽  
pp. 201-218 ◽  
Author(s):  
J.H.B. Smith
Keyword(s):  
Slenderness Ratio ◽  
Transport Aircraft ◽  
Supersonic Transport ◽  
Drag Ratio

SummaryPrevious work by R. T. Jones on the drag minimisation of elliptic wings is extended to the case of the slewed wing with thickness. These results are used to calculate lift/drag ratios of idealised configurations related to a supersonic transport aircraft. The values of lift/drag ratio and optimum slenderness ratio found are comparable with those calculated earlier in studies of delta-like plan forms.

scholarly journals Quantitative of Badminton Practice Based on Wireless Sensor Network

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hui Huang ◽  
Yibo Zhang ◽  
Geng Pang ◽  
Aoting Ye
Keyword(s):  
Evaluation Model ◽  
Accurate Method ◽  
Lower Limbs ◽  
Fuzzy Evaluation ◽  
Analytic Hierarchy ◽  
The Public ◽  
Left And Right ◽  
Hierarchy Process ◽  
Effective Analysis

In recent years, badminton sports have attracted the public and the majority of young students. Badminton training has received extensive attention in the field of sports. However, there is currently no effective and accurate method for effective analysis of badminton training. In order to solve this problem, this paper combines the training teaching theory and the representation training theory and applies the fuzzy algorithm to construct the fuzzy evaluation model based on the analytic hierarchy process. After the experiment, the test scores of the sports quality of the two groups of badminton special students were improved. Through the screening of the seven functional modes of action, it was found that the special students’ left and right symmetry differences were obvious, the lower limbs were not stable, the core area was weak, and the muscle control ability on both sides of the spine needed to be strengthened.

SOFT ERROR RATE ESTIMATION FOR COMBINATIONAL LOGIC IN PRESENCE OF SINGLE EVENT MULTIPLE TRANSIENTS

2014 ◽  
Vol 23 (06) ◽  
pp. 1450091 ◽  
Author(s):  
RAMIN RAJAEI ◽  
MAHMOUD TABANDEH ◽  
MAHDI FAZELI
Keyword(s):  
Error Rate ◽  
Radiation Effects ◽  
Fault Injection ◽  
Estimation Method ◽  
Accurate Method ◽  
Vlsi Circuits ◽  
Soft Error ◽  
Accurate Estimation ◽  
Fast Method ◽  
Soft Error Rate

Fast and accurate estimation of soft error rate in VLSI circuits is an essential step in a soft error tolerant ASIC design. In order to have a cost effective protection against radiation effects in combinational logics, an accurate and fast method for identification of most susceptive gates and paths is needed. In this paper, an efficient, fast and accurate method for soft error propagation probability (SEPP) estimation is presented and its performance is evaluated. This method takes into account all three masking factors in multi cycles. It also considers multiple event transients as a new challenge in soft error tolerant VLSI circuit design. Compared with Monte Carlo (MC) simulation-based fault injection method, our SEPP estimation method has a high level of accuracy (with less than 2% difference) while offering 1000× speedup as compared with MC-based simulation.

Aircraft descent performance based on flight data

2021 ◽  
pp. 1-20
Author(s):  
C.A. Hall ◽  
S.R. Burnell ◽  
A.P. Deshpande
Keyword(s):  
Mechanical Energy ◽  
Time History ◽  
Gravitational Potential Energy ◽  
Aircraft Engines ◽  
Flight Data ◽  
Average Value ◽  
Fuel Burn ◽  
Air Speed ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract There are significant variations in the fuel consumption of aircraft during the descent phase of a flight. This paper uses aircraft flight data measurements to develop an improved understanding of these variations. A model of the aircraft engines is developed that is matched to flight data and shown to reproduce the time history of engine parameters. This model is used to determine the overall engine efficiency at each point during a descent. This enables an energy breakdown to be completed, in terms of mechanical energy from fuel, gravitational potential energy and kinetic energy. During descent, the aircraft engines operate at low overall pressure ratios corresponding to low fuel flow rates and low overall efficiencies. On average, the engine overall efficiency during descent is one-third of cruise efficiency. The airframe aerodynamic performance is deteriorated during descent with an average lift-to-drag ratio that is 87% of the average value at cruise. There are also large variations in air-track efficiency, and for the flights analysed the great circle descent distance was found to be 85% of the average descent air distance. To minimise fuel burn, flights should cruise as far as possible before starting descent and follow a trajectory with the shortest possible air distance. The descent air speed should be set to maximise the aircraft lift-to-drag ratio. Such descents could save up to 0.5% of the total aircraft mass in fuel.

Methodology of estimating the number of inhabitants to assess the population exposure to environmental noise in Japan

2021 ◽  
Vol 263 (2) ◽  
pp. 4312-4321
Author(s):  
Shota Suda ◽  
Akiko Sugahara ◽  
Yasuhiro Hiraguri ◽  
Kazunori Harada ◽  
Takuya Oshima ◽  
...  
Keyword(s):  
Accurate Method ◽  
Environmental Noise ◽  
Assessment Process ◽  
Population Exposure ◽  
Geospatial Information ◽  
Risk Assessment Process ◽  
The Public ◽  
Web Scraping ◽  
Privacy Violation ◽  
Limited Accuracy

Population exposure has been used in the risk assessment process for environmental noise. The number of inhabitants is essential data for the evaluation of population exposure. However, such data is not opened to the public to prevent privacy violation. There are several existing methods for the estimation of the number of habitants, but only with limited accuracy. The purpose of this study is to propose a more accurate method for estimating the number of inhabitants using web scraping techniques and numerical maps issued by the Geospatial Information Authority of Japan. The number of inhabitants is estimated from the number of households and the census. The number of households is calculated based on the total number of housing that is extracted from using web scraping techniques. The proposed method is found to present a better accuracy of the number of inhabitants for the detached houses while the estimation for apartment houses should be still improved.

scholarly journals Experimental Study of the Combustion of Kerosene and Binary Surrogate in the Model Combustion Chamber

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Sergey S. Matveev ◽  
Ivan V. Chechet ◽  
Aleksander S. Semenikhin ◽  
Valerii Y. Abrashkin ◽  
Sergey V. Lukachev ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Atmospheric Pressure ◽  
Liquid Fuel ◽  
Pressure Ratio ◽  
Operation Mode ◽  
Hazardous Substance ◽  
Feed System ◽  
Fuel Feed ◽  
Fuel Burn ◽  
Burn Rate

The purpose of this paper is to conduct experimental research of hazardous substance emissions at the simulated combustion chamber output. The experiment was carried in a simulated combustion chamber. The combustion chamber included a burner device; a liquid fuel feed system; and a flame tube with two rows of mixing holes and one row of cooling holes. The combustion chamber operation mode was φ = 0.435, Tpreheat = 423 K, and the atmospheric pressure. The liquid fuel burn rate was 0.77 g/s. The pressure ratio in the combustion chamber remained constant at ΔP = 3%. Two types of fuel were used: aviation kerosene of Russia’s TS-1 brand and the fuel surrogate was n-decane mixture (C10H22) with benzene additions (C6H6). The benzene additions were 5% through 30% (n-decane/benzene: 95/5, 90/10, 85/15, 80/20, 75/25, and 70/30).

Microcombustors Based on Controllable Solid Fuel Elements

2003 ◽  
Author(s):  
Brian E. English ◽  
Heather H. DiBiaso ◽  
Mark G. Allen
Keyword(s):  
Solid Fuel ◽  
Reaction Times ◽  
Heat Losses ◽  
Solid Fuels ◽  
Solid Propellants ◽  
Combustion Chambers ◽  
Gas Generation ◽  
Fuel Burn ◽  
Burn Rate ◽  
Composite Solid

This paper focuses on the control of solid-fuel burn rate by controlling the solid-fuel chemistry or by controlling heat losses. Laser cutting and lamination have been used to fabricate milli-scale test structures to characterize burn rates of composite solid fuel. The base ingredients for the solid fuels tested were phase-stabilized ammonium nitrate (PSAN), ammonium perchlorate (AP), and sodium azide (SA). These base ingredients were tested alone or mixed with hydroxyl-terminated poly-butadiene (HTPB) plus various accelerants. Several experiments were performed to test the controllability of composite solid fuels. Burn-rate tests at atmospheric pressure consisted of 250 to 500 micron deep square combustion chambers packed with fuel and resistively heated on the top surface until combustion was achieved. Experiments were also performed to increase burn rate through chamber pressurization. Reaction times for a set amount of fuel were observed to increase exponentially as nozzle diameter was decreased. Finally, combustion chamber geometry was altered to control reaction propagation by increasing localized heat losses. A 500 micron thick triangular chamber was fabricated and ignited at the larger end, allowing the reaction to propagate toward the triangle tip. These results indicate that controllable actuation of solid propellants on the microscale for non-thrust, gas generation actuator applications is feasible.

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