Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study

2009 ◽  
Author(s):  
Fernando Colmenares Quintero ◽  
Rob Brink ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
Juan Carlos Colmenares Quintero ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Short Range ◽  
Operating Cost ◽  
Constant Volume ◽  
Superior Performance ◽  
Wave Rotor ◽  
Environmental Aspects ◽  
Direct Operating Cost ◽  
Combustion Technology ◽  
Further Development

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behaviour. Wave rotor combustion provides semi-constant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary Multidisciplinary Design Framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, acquisition cost of the engine is higher, but engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emissions requirements.

Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Ramón F. Colmenares Quintero ◽  
Rob Brink ◽  
Stephen Ogaji ◽  
Pericle Pilidis ◽  
Juan C. Colmenares Quintero ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Short Range ◽  
Flow Behavior ◽  
Operating Cost ◽  
Constant Volume ◽  
Superior Performance ◽  
Wave Rotor ◽  
Environmental Aspects ◽  
Combustion Technology ◽  
Further Development

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behavior. Wave rotor combustion provides semiconstant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary multidisciplinary design framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions, and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, the acquisition cost of the engine is higher, but the engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emission requirements.

Possibilities of Cost Reduction with All-Wing Aircraft

1965 ◽  
Vol 69 (659) ◽  
pp. 744-749 ◽  
Author(s):  
C. H. Lee
Keyword(s):  
Cost Reduction ◽  
Design Problem ◽  
Short Range ◽  
Operating Cost ◽  
Design Features ◽  
General Survey ◽  
General Argument ◽  
Sequence Of Events ◽  
Range Transport ◽  
Direct Operating Cost

The aim of this paper is to show how design improvements may lead to a reduction in direct operating cost, pence per passenger mile. In all the comparisons made it is assumed that equal standards of equipment, accommodation, powerplant efficiency, and so forth, apply and that equal skill and standards apply in manufacturing; differences therefore are due to design features. The paper is in two main sections:(1) A Satellite's eye-view of the whole design problem of the cheap short-range transport aeroplane.(2) A more detailed description of two specific examples which illustrate the conclusions drawn from the general survey.The first part is historically fiction but technically fact; the second part (despite the temptation to interchange the above two nouns and adjectives) is, I claim, fact both historically and technically.I have departed from the historical sequence of events for the first part because we have now realised that it is possible to present in a comprehensive general argument the rather confused mass of data, ideas, techniques, inspirations and false trails that, in the course of time, led us to an enthusiasm for the all-wing Aerobus.

Gel Electrolyte Based Supercapacitors with Higher Capacitances and Lower Resistances than Devices with a Liquid Electrolyte

MRS Advances ◽  
2018 ◽  
Vol 3 (22) ◽  
pp. 1261-1267 ◽  
Author(s):  
Belqasem Aljafari ◽  
Arash Takshi
Keyword(s):  
Polymer Electrolytes ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Liquid Electrolyte ◽  
Gel Electrolyte ◽  
Superior Performance ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Gel Electrolytes ◽  
Further Development

ABSTRACTRecently, gel polymer electrolytes (GPEs) have been drawn noteworthy attention for different applications, specifically, for supercapacitors. GPEs could become an excellent substitute to liquid electrolytes (LEs) for making flexible and more durable devices. The performance of two different electrolytes (GPEs and LEs) in multi-wall carbon nanotube based supercapacitors were investigated. In spite of significantly lower conductivity of GPEs than LEs, devices with the gel electrolyte presented a superior performance. More focused has been given in this work on demonstrating the performance of supercapacitors based on GPEs and LEs at different concentrations of the acids ranging from 1M to 3M. Both electrolytes have been characterized at room temperature by making supercapacitors and using cyclic voltammetry, charging-discharging, electrochemical impedance spectroscopy, and leakage tests. The experimental results showed that GPE devices had much better capacitances and resistances compare to the LE based devices. Moreover, the capacitances of all devices were increased proportionally with the increase in the concentration from 1M to 3M, and the resistances were increased inversely with the decreased of concentration. The promising results from the gel electrolytes is encouraging for further development of flexible and high capacitance energy storage devices.

scholarly journals Enabling the potential of hybrid electric propulsion through lean-burn-combustion turbofans

2021 ◽  
Vol 5 ◽  
pp. 164-176
Author(s):  
Stavros Vouros ◽  
Mavroudis Kavvalos ◽  
Smruti Sahoo ◽  
Konstantinos Kyprianidis
Keyword(s):  
Electric Propulsion ◽  
Direct Injection ◽  
Operating Cost ◽  
Pollutant Emissions ◽  
Civil Aviation ◽  
Lean Burn ◽  
Lean Direct Injection ◽  
Direct Operating Cost ◽  
Hybrid Electric ◽  
The Impact

Hybrid-electric propulsion has emerged as a promising technology to mitigate the adverse environmental impact of civil aviation. Boosting conventional gas turbines with electric power improves mission performance and operability. In this work the impact of electrification on pollutant emissions and direct operating cost of geared turbofan configurations is evaluated for an 150-passenger aircraft. A baseline two-and-a-half-shaft geared turbofan, representative of year 2035 entry-into-service technology, is employed. Parallel hybridization is implemented through coupling a battery-powered electric motor to the engine low-speed shaft. A multi-disciplinary design space exploration framework is employed comprising modelling methods for multi-point engine design, aircraft sizing, performance and pollutant emissions, mission and economic analysis. A probabilistic approach is developed considering uncertainties in the evaluation of direct operating cost. Sensitivities to electrical power system technology levels, as well as fuel price and emissions taxation are quantified at different time-frames. The benefits of lean direct injection are explored along short-, medium-, and long-range missions, demonstrating 32% NO<italic><sub>x</sub></italic> savings compared to traditional rich-burn, quick-mix, lean-burn technologies in short-range operations. The impact of electrification on the enhancement of lean direct injection benefits is investigated. For hybrid-electric powerplants, the take-off-to-cruise turbine entry temperature ratio is 2.5% lower than the baseline, extending the corresponding NO<italic><sub>x</sub></italic> reductions to the level of 46% in short-range missions. This work sheds light on the environmental and economic potential and limitations of a hybrid-electric propulsion concept towards a greener and sustainable civil aviation.

scholarly journals ESTIMATING CAPITAL AND OPERATIONAL COSTS OF BACKHOE SHOVELS

2012 ◽  
Vol 18 (3) ◽  
pp. 378-385 ◽  
Author(s):  
Ahmad Reza Sayadi ◽  
Ali Lashgari ◽  
Mohammad Majid Fouladgar ◽  
Miroslaw J. Skibniewski
Keyword(s):  
Feasibility Study ◽  
Cost Estimation ◽  
Construction Projects ◽  
Cost Model ◽  
Operating Cost ◽  
Principal Component ◽  
Feasibility Studies ◽  
Project Managers ◽  
Cost Models ◽  
Optimum Type

Material loading is one of the most critical operations in earthmoving projects. A number of different equipment is available for loading operations. Project managers should consider different technical and economic issues at the feasibility study stage and try to select the optimum type and size of equipment fleet, regarding the production needs and project specifications. The backhoe shovel is very popular for digging, loading and flattening tasks. Adequate cost estimation is one of the most critical tasks in feasibility studies of equipment fleet selection. This paper presents two different cost models for the preliminary and detailed feasibility study stages. These models estimate the capital and operating cost of backhoe shovels using uni-variable exponential regression (UVER) as well as multi-variable linear regression (MVLR), based on principal component analysis. The UVER cost model is suitable for quick cost estimation at the early stages of project evaluation, while the MVLR cost function, which is more detailed, can be useful for the feasibility study stage. Independent variables of MVLR include bucket size, digging depth, dump height, weight and power. Model evaluations show that these functions could be a credible tool for cost estimations in prefeasibility and feasibility studies of mining and construction projects.

Next Generation Turboprop Gearboxes

1982 ◽  
Author(s):  
W. L. McIntire ◽  
D. A. Wagner
Keyword(s):  
Operating Cost ◽  
Past Experience ◽  
Reduction Ratio ◽  
Next Generation ◽  
Propulsion Systems ◽  
Aircraft Systems ◽  
General Arrangement ◽  
Significant Interest ◽  
Direct Operating Cost ◽  
New Generation

A new generation of fuel-efficient turboprop propulsion systems is under consideration now that fuel is a significant portion of the direct operating cost of aircraft. Systems in the 5000- to 15,000-hp (3730- to 11,185-kW) range that use conventional propellers or the new propfan are being studied. Reduction gearing for this next generation of turboprops is of significant interest due to new requirements for cruise speed life, and reliability. Detroit Diesel Allison’s past experience with the T56 family of turboprop reduction gearboxes is recounted. Probable requirements of the next generation of reduction gearboxes are discussed since new requirements for gearboxes combined with past experience should determine the profile of the next generation of gearboxes. A discussion of gearbox general arrangement and its impact on airframe installation is included, along with comments on reduction ratio, gear arrangement, accessory drives, reliability goals, and probable technology needs.

Future Aero-Engines’ Optimisation for Minimal Operating Costs

2008 ◽  
Author(s):  
Fernando Colmenares ◽  
Daniele Pascovici ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
Alexander Garci´a ◽  
...  
Keyword(s):  
Public Awareness ◽  
Operating Cost ◽  
Design Tool ◽  
Commercial Aircraft ◽  
Commercial Aviation ◽  
Passenger Traffic ◽  
Direct Operating Cost ◽  
Promising Solution ◽  
Aero Engines ◽  
Bypass Ratio

While aircraft environmental performance has been important since the beginnings of commercial aviation, continuously increasing passenger traffic and a rise in public awareness have made aircraft noise and emissions two of the most pressing issues hampering commercial aviation growth today. The focus of this study is to determine the feasibility of vey-high bypass ratio, geared and contra-rotating aero engines (see figures 2–4) for short range commercial aircraft in terms of economics and environment. This involves optimising the engines’ design point to minimise the direct operating cost and evaluating the economic and environmental impact. The results present a great potential benefit of the geared turbofan compared to high BPR one (baseline) to reduce DOC; however this may involve NOx penalties, that is an increase of 11.6% in comparison to the baseline. The CRTF engine seems to be, at least according to the simulations, a very promising solution in terms of environmental and economical performance. This is one on the series of work that would be carried out using the design tool proposed. Further work on the assessment of more radical turbofans at different economical and environmental scenarios would be published when completed.

scholarly journals Cruise Flight Performance Optimization for Minimizing Green Direct Operating Cost

2019 ◽  
Vol 11 (14) ◽  
pp. 3899 ◽  
Author(s):  
Tian ◽  
Wan ◽  
Ye ◽  
Xing
Keyword(s):  
Environmental Effects ◽  
Performance Optimization ◽  
Meteorological Data ◽  
Operating Cost ◽  
Numerical Test ◽  
Flight Performance ◽  
Time Dynamic ◽  
Direct Operating Cost ◽  
Greenhouse Effects ◽  
Cruise Flight

To cope with the environmental impact of aviation and pollution problems in the future, airlines need to assess environmental impacts and offer countermeasures in advance. In order to measure the influence of environment on the airlines’ operational costs, this paper establishes an aircraft green direct operating cost (GDOC) model to quantify adverse environmental effects, such as air pollution and greenhouse effects, into the direct operating cost (DOC). Furthermore, fuel consumption, flight time, and distance in the cruising stage account for about 80% of the entire flight mission, and optimizing cruise flight performance can contribute greatly to reduce GDOC. Therefore, this paper sets up an optimal control model to minimize GDOC, establishes a discrete time dynamic system for optimizing the cruise altitude and speed profiles, and searches the optimal results by using dynamic programming. Besides, as meteorological conditions affect aircraft aerodynamics, fuel flow rate, contrail formation, and so on, this paper analyzes meteorological uncertainty by using historic meteorological data. Finally, a route is selected as an example, and the rationality of the optimal results is proven by comparing GDOC with DOC. The results and discussion of the numerical test also show that environmental effects on aircraft operation can be reduced significantly by adopting GDOC as the optimization objective, especially the contrail cost, and the step-climb cruise mode can further reduce GDOC effectively.

Optimum Conditions for the Operation of Airline Aircraft

1953 ◽  
Vol 57 (516) ◽  
pp. 823-824
Author(s):  
J. M. Stephenson
Keyword(s):  
Fuel Consumption ◽  
Operating Cost ◽  
Practical Case ◽  
Optimum Conditions ◽  
Realistic Approach ◽  
Direct Operating Cost ◽  
Usual Concept ◽  
Airline Company

In A. H. Stratford's interesting note in the August Journal, he assumes that an airline is presented with an aircraft of given performance, and must decide what is the best range for it to fly. Surely the practical case is the exact opposite: that an operator wishes to carry passengers or freight between two given points, and must choose between perhaps three or four available types of aircraft. Moreover, it is up to the operator to tell the manufacturers which feature he wants improved (e.g. fuel consumption, take-off distance, and so on), when he is ready to order replacements.Secondly, Mr. Stratford wishes to replace the usual concept of direct operating cost per payload ton mile by that of per cent, profit, as a measure of the efficiency of operation over a certain route. While this may be a more realistic approach to the problem of a private airline company, operating over a single route, its merit is not so obvious for the large national or subsidised airlines, which are often required to fly unprofitable routes.

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