On the benefits of lower Mach number aircraft cruise

Abstract The paper reviews the issue of cruise Mach number and addresses the benefits of operating subsonic commercial aircraft at speeds below the long-range cruise speed. The case considered is the flight of transport aircraft for flight segments up to 1,000nm. It is shown that the fuel burned is decreased by as much as 1·8% on a nominal 1,000nm stage length for operation around the long-range cruise Mach number, or below. This is achieved at a cost of a marginal delay on each flight segment (less than three minutes). The longer flight time is likely not to affect the daily operation of the aircraft. The fuel saving is compounded, because the gross take-off weight (GTOW) is recalculated to take into account the reduced fuel consumption at each flight segment. The analysis into the environmental benefits includes the reduction in,andemissions, and the heat released in the high atmosphere. Sensitivity analyses are carried out on the take-off weight, on the aerodynamic coefficients, on the transonic drag rise and the weight uncertainty. It is predicted that the optimal operation of the example aircraft over a nominal 1,000nm route can reduce the fuel consumption by as much as 150,000kg per year in comparison with an operation at the long-range Mach number. The aircraft model has a maximum take-off weight of 170,000kg and is powered by two GE CF6-80C2 engines.

Download Full-text

170 Social and Environmental Benefits of Virtual Fracture Clinics in Trauma and Orthopaedic Surgery: Reduced Patient Travel Time, Patient Cost and Air Pollutant Emissions

British Journal of Surgery ◽

10.1093/bjs/znab259.444 ◽

2021 ◽

Vol 108 (Supplement_6) ◽

Author(s):

J Fort ◽

H Hughes ◽

U Khan ◽

A Glynn

Keyword(s):

Travel Time ◽

Fuel Consumption ◽

Travel Distance ◽

Air Pollutant ◽

Environmental Benefits ◽

Pollutant Emissions ◽

Patient Cost ◽

Travel Costs ◽

Patient Travel ◽

Travel Burden

Abstract Aim Several papers have analysed the clinical benefits and safety of Virtual Fracture Clinics (VFCs). A significant increase in the use of Trauma and Orthopaedic (T&O) VFCs was seen during the COVID-19 pandemic. This study aims to investigate the social impact of VFCs on the travel burden and travel costs of T&O patients, as well as the potential environmental benefits in relation to fuel consumption and travel-related pollutant emissions. Method All patients referred for T&O VFC review from March 2020 to June 2020 were retrospectively analysed. The travel burden and environmental impacts of hypothetical face-to-face consultations were compared with these VFC reviews. The primary outcomes measured were patient travel time saved, patient travel distance saved, patient cost savings and reduction in air-pollutant emissions. Results Over a four-month period, 1359 VFC consultations were conducted. The average travel distance saved by VFC review was 88.6 kilometres (range 3.3-615), with an average of 73 minutes (range 9-390) of travel-time saved. Patients consumed, on average, 8.2 litres (range 0.3-57.8) less fuel and saved an average of €11.02 (range 0.41-76.59). The average reduction in air-pollutant vehicle emissions, including carbon dioxide, carbon monoxide, nitric oxides and volatile organic compounds was 20.3 kilograms (range 0.8-140.8), 517.3 grams (g) (range 19.3-3592.3), 38.1g (range 1.4-264.8) and 56.9g (range 2.1-395.2), respectively. Conclusions VFCs reduce patient travel distance, travel time and travel costs. In addition, VFCs confer significant environmental benefits through reduced fuel consumption and reduction of harmful environmental emissions.

Download Full-text

Effects of Descent Flight-Path Angle on Fuel Consumption of Commercial Aircraft

Journal of Aircraft ◽

10.2514/1.c033911 ◽

2019 ◽

Vol 56 (1) ◽

pp. 313-323 ◽

Cited By ~ 1

Author(s):

Enis T. Turgut ◽

Oznur Usanmaz ◽

Mustafa Cavcar ◽

Tuncay Dogeroglu ◽

Kadir Armutlu

Keyword(s):

Fuel Consumption ◽

Flight Path ◽

Commercial Aircraft ◽

Flight Path Angle

Download Full-text

Analysis of Environmental Benefits of Shore Power for Preventing and Controlling Air Pollution Caused by Vessels at Berth

E3S Web of Conferences ◽

10.1051/e3sconf/20185304036 ◽

2018 ◽

Vol 53 ◽

pp. 04036 ◽

Cited By ~ 1

Author(s):

Cheng Jieling ◽

Li Haibo

Keyword(s):

Energy Conservation ◽

Fuel Consumption ◽

Air Pollutants ◽

Emission Reduction ◽

Electric Energy ◽

Air Pollutant ◽

Environmental Benefits ◽

Pollutant Emission ◽

Current Status ◽

Fuel Consumption Rate

When vessels are berthed at ports, the air pollutants emitted by auxiliary engines will cause severe pollution to the ports and surrounding environments. In view of this situation, the author first summarizes the Chinese policies and policies of foreign countries on emission of air pollutants from vessels at berth, and then analyses the current status of and measures for control of air pollutant emission from vessels at berth. Secondly, the author analyses the environmental benefits of using shore power for better controlling air pollutant emission from vessels at berth, compares vessels using shore power with vessels using generated power in the energy conservation and emission reduction effects based on the fuel consumption rate of different auxiliary engines and current status of pollutant emission from power generation in China etc., analyses the current status of shore power application in China, estimates the energy conserved and emission reduced when shore power is used by vessels at berth. Thirdly, the author identifies the scale of electric energy replacement by, and environmental benefits of, shore power at ports in China. This paper delivers innovative approaches to the comparison between the effects of energy conservation and emission reduction based on fuel consumption rates of different auxiliary engines and estimation of conserved energy and reduced emission.

Download Full-text

Multi-Disciplinary Impact of Engine Parameters Upon Transport Aircraft Climb Fuel Consumption

53rd AIAA Aerospace Sciences Meeting ◽

10.2514/6.2015-1677 ◽

2015 ◽

Author(s):

Timothy T. Takahashi ◽

Christopher E. Gedeon

Keyword(s):

Fuel Consumption ◽

Transport Aircraft

Download Full-text

Design and Operation of a Hybrid CCHP System Including PV-Wind Devices

Volume 6A: Energy ◽

10.1115/imece2013-64513 ◽

2013 ◽

Cited By ~ 3

Author(s):

J. L. Wang ◽

J. Y. Wu ◽

C. Y. Zheng

Keyword(s):

Fuel Consumption ◽

Internal Combustion Engines ◽

High Efficiency ◽

Waste Heat ◽

Internal Combustion ◽

Energy System ◽

Optimal Operation ◽

Combustion Engines ◽

Wind System ◽

Fuel Price

CCHP systems based on internal combustion engines have been widely accepted as efficient distributed energy resources systems. CCHP systems can be efficient mainly because that the waste heat of engines can be recovered and used. If the waste heat is not used, CCHP systems may not be beneficial choices. PV-wind systems can generate electricity without fuel consumption, but the electric output depends on the weather, which is not reliable. A PV-wind system can be integrated into a CCHP system to form a higher efficient energy system. Actually, a hybrid energy system based on PV-wind devices and internal combustion engines has been studied by many researchers. But the waste heat of the engine is seldom considered in the previous work. Researches show that, 20∼30% energy can be converted into electricity by a small size engine while more than 70% is released. If the waste heat is not recovered, the system cannot reach a high efficiency. This work aims to analyze a hybrid CCHP system with PV-wind devices. Internal combustion engines are the prime movers whose waste heat is recovered for house heating or driving absorption chillers. PV-wind devices are added to reduce the fuel consumption and total cost. The optimal design method and optimal operation strategy are proposed basing on hourly analyses. Influences of the device cost and fuel price on the optimal dispatch strategies are discussed. Results show that all of the excess energy from the PV-wind system is not worth being stored by the battery. The hybrid CCHP system can be more economical and higher efficient in the studied case.

Download Full-text

Advanced Turbofan Engines for Low Fuel Consumption

Volume 1B: General ◽

10.1115/78-gt-192 ◽

1978 ◽

Author(s):

William Sens

Keyword(s):

Fuel Consumption ◽

Advanced Technology ◽

Commercial Aircraft ◽

New Production ◽

Turbofan Engine ◽

Fuel Savings ◽

Turbofan Engines ◽

Aircraft Fuel ◽

Design Characteristics ◽

Year 2000

The anticipated commercial aircraft fuel usage through the year 2000 is divided into three categories: that which will be consumed by existing engines, new production of current type engines, and new turbofan engines with advanced technology. Means of improving fuel consumption of each of these engine categories will be reviewed and the potential fuel savings identified. The cycle selection and design characteristics of an advanced turbofan engine configuration will be discussed and the potential improvements in fuel consumption and economics identified.

Download Full-text

Optimal Operation of Renewable Distributed Generators (DGs) and its Environmental Benefits

Encyclopedia of Renewable and Sustainable Materials ◽

10.1016/b978-0-12-803581-8.11008-2 ◽

2020 ◽

pp. 619-627

Author(s):

Chandan K. Chanda ◽

Dipanjan Bose

Keyword(s):

Optimal Operation ◽

Environmental Benefits ◽

Distributed Generators

Download Full-text

Analyzing commercial aircraft fuel consumption during descent: A case study using an improved K-means clustering algorithm

Journal of Cleaner Production ◽

10.1016/j.jclepro.2019.02.235 ◽

2019 ◽

Vol 223 ◽

pp. 869-882 ◽

Cited By ~ 10

Author(s):

Qing Zhu ◽

Jun Pei ◽

Xinbao Liu ◽

Zhiping Zhou

Keyword(s):

Fuel Consumption ◽

Clustering Algorithm ◽

Commercial Aircraft ◽

Aircraft Fuel

Download Full-text

On the Evaluation of Negative Altitude Requirement for Flutter Speed Boundary of Transport Aircraft and UAV

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.225.397 ◽

2012 ◽

Vol 225 ◽

pp. 397-402 ◽

Cited By ~ 2

Author(s):

Erwin Sulaeman

Keyword(s):

Mach Number ◽

Atmospheric Condition ◽

Aircraft Design ◽

Maximum Speed ◽

Flight Safety ◽

Transport Aircraft ◽

Aeroelastic Instability ◽

Flight Envelope ◽

Constant Altitude ◽

Standard Regulation

To maintain flight safety, all transport aircraft designs should satisfy airworthiness standard regulation. One fundamental issue of the aircraft design that relates directly to flight safety as well as commercial aspect of the aircraft is on the evaluation of the maximum speed within the designated flight envelope. In the present work, a study is performed to evaluate the negative altitude requirement related to aeroelastic instability analysis as one requirement that should be fulfilled to design the maximum speed. An analytical derivation to obtain the negative altitude is performed based on the airworthiness requirement that a transport airplane must be designed to be free from aeroelastic instability within the flight envelope encompassed by the dive speed or dive Mach number versus altitude envelope enlarged at all points by an increase of 15% in equivalent airspeed at both constant Mach number and constant altitude. To take into account variation in atmospheric condition as function of altitude, the international standard regulation is used as referenced. The analysis result shows that a single negative altitude can be obtained using these criteria regardless of the dive speed or dive Mach number. A further discussion on the application of the negative altitude concept to UAV (Unmanned Aerial Vehicle), in relation to UAV Standard Airworthiness Requirement STANAG 4671, is presented.

Download Full-text