The Multi-Objective Optimization of the Air Transportation Fleet Structure (original) (raw)
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Multi-objective optimization applied for planning of regional European airline
Archives of Transport, 2014
Fleet planning is very important elements in the airlines planning process. Fleet planning should answer the question which types of aircraft are required and how many of them are required taking into account the current and future transportation needs. Decision-making in the field of operations has a character of engineering. This process requires consideration of many factors, dependencies and criteria. The article presents the decision problem formulated in the form of a multi-objective mathematical model. This work preliminarily determines the structure of the transportation system which performs carriages on the local routes.
INTEGRATED OPTIMIZATION OF AIR TRANSPORTATION SYSTEMS (AIRCRAFT AND NETWORK)
Doctoral Thesis, 2020
The determination of optimal aerial transport networks and their associated flight frequencies is crucial for the strategic planning of airlines, as well as for carrying out market research, and for aircraft and crew rostering. In addition, optimum airplane types for the selected networks are crucial to improve revenue and to provide reduced operating costs. The present research proposes an innovative Multidisciplinary Design Optimization (MDO) framework with the objective to optimize a highly detailed airplane design simultaneously with the associated airline network, for a given area of operations and associated demand, in a multiobjective-multivariable problem. In this framework, the aircraft design and network computation modules are executed independently in sequenced blocks and wrapped into a genetic algorithm in the optimization process. Two sets of objective functions were studied, according to the optimization scope: airline operations optimization (considering Network Profit and Network Direct Operational Cost as objective functions) and airline/aircraft manufacturer optimization (considering Network Profit and manufacturer´s Cash Flow Net Present Value as objective functions). In the aircraft design module, several design parameters are used to represent the airplane in finest detail with accurate aerodynamic, stability and control, and propulsion characteristics, necessary for the mission analysis of each route segment considered in each leg of the network. The accurate calculation of a realistic mission operational profile was performed thanks to the application of an Artificial Neural Network for aerodynamic coefficient estimation and a robust generic turbofan propulsion model. In the network computation module, disciplines related to network optimization, mission performance and airline economics are integrated. The network optimization module is performed in a sub-optimization framework using an elaborated gravitational demand model to predict passenger flows between city-pairs. Under this scope, four types of simulation scenarios, considering major Brazilian airports, were evaluated in order to apply the above described methodology: determination of the optimum aircraft design in a given five airports network, determination of the optimum five airports network for a given aircraft design, simultaneous optimization of aircraft design and network (five and ten airports) and simultaneous optimization of a fleet of three aircraft and a network of twenty airports. Results demonstrated significant financial advantages for airlines on using the mentioned objective functions instead of the conventional minimization of Direct Operational Costs approach.
Multi-Objective Aircraft Optimization for Minimum Cost and Emissions over Specific Route Networks
The 26th Congress of ICAS and 8th AIAA ATIO, 2008
Historically, maximizing profits for corporate shareholders has been the primary goal for aircraft designers. Due to climate change concerns, environmental performance is quickly becoming a major design focus. A methodology to design one or more aircraft to satisfy demand on a given route network is described. The objectives are to minimize direct operating costs, CO 2 emissions and NO X emissions. A hierarchical decomposition is used with discipline-specific optimization algorithms. A modified version of the NSGA-II multi-objective genetic algorithm is implemented in the system level aircraft design subspace. The CPLEX integer solver is used in the fleet assignment subspace. Results are presented for a test problem that involves designing a single aisle commercial aircraft for a route network consisting of 4 cities and 8 route segments. A Pareto front is found and the characteristics of the optimal aircraft designs and fleet assignment solutions are examined. The results show a definitive trades between operating costs and NO X emissions and CO 2 emissions and NO X emissions. Operating costs and CO 2 emissions are strongly related, with little if any trade off evident. All designs show benefits from using higher bypass ratio engines and thicker, higher aspect ratio wings than today's single aisle commercial aircraft.
INTEGRATED AIRCRAFT DESIGN AND AIR TRANSPORT NETWORK OPTIMIZATION
PhD Qualify Presentation - Techological Institute of Aeronautics, 2018
The determination of optimal aerial transport networks and their associated flight frequencies is crucial for the strategic planning of airlines, as well as for carrying out market research, and for aircraft and crew rostering. In addition, optimum airplane types for the selected networks are crucial to improve revenue and to provide reduced operating costs. The present study proposes an innovative approach to determine the optimal aerial transport network simultaneously with the determination of the optimum fleet for that network, composed of three types of airplanes (network and vehicle integrated design). The network profit is maximized. The passenger’s demands between the airports are determined via a gravitational model. An embedded linear programming solution is responsible for obtaining potential optimal network configurations. The optimum fleet combination is determined from a database of candidate aircraft designs via genetic algorithm. A truly realistic airplane representation is made possible thanks to accurate surrogate models for engine and aerodynamics is adopted. An accurate engine deck encompassing a compression map and an innovative engine weight calculation besides an aerodynamical artificial neural network module enable a high-degree of accuracy for the mission analysis. The proposed methodology is applied to obtain the optimum network comprised of twenty main Brazilian airports and corresponding fleet.
The problem of choice of light transport aircraft characteristics
2013
Europe is one of the densely populated continents on Earth. A characteristic feature of the European air transport service market is co-existence of several and large communication centres performing trans-continental links and dense net of local links between the majority of small cities and tourist resorts. Europe is an exceptional area with unique properties favouring regional development of the air transport system of light aircraft with the use of small and medium airports. Europe has a huge partly unused potential of airports and landing grounds which can be the basis for creating a competitive travel offer around Europe by light passenger aircrafts. They can use less busy airports and adjusted and re-qualified landing grounds as well as natural landing fields. Operators and entrepreneurs interested in starting new air transport businesses report about missing modern aircrafts. The present paper shows the algorithm of optimal selection of the designing parameters of the aircra...
Next generation aircraft design considering airline operations and economics
2018 AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2018
Traditional approaches to design and optimization of a new system often use a systemcentric objective and do not take into consideration how the operator will use this new system alongside other existing systems. When the new system design is incorporated into the broader group of systems, the performance of the operator-level objective can be sub-optimal due to the unmodeled interaction between the new system and the other systems. Among the few available references that describe attempts to address this disconnect, most follow an MDO-motivated sequential decomposition approach of first designing a very good system and then providing this system to the operator who, decides the best way to use this new system along with the existing systems. This paper addresses this issue by including aircraft design, airline operations, and revenue management "subspaces"; and presents an approach that could simultaneously solve these subspaces posed as a monolithic optimization problem rather than the traditional approach described above. The monolithic approach makes the problem an expensive Mixed Integer Non-Linear Programming problem, which are extremely difficult to solve. To address the problem, we use a recently developed optimization framework that simultaneously solves the subspaces to capture the "synergy" in the problem that the previous decomposition approaches did not exploit, addresses mixed-integer/discrete type design variables in an efficient manner, and accounts for computationally expensive analysis tools. This approach solves an 11-route airline network problem consisting of 94 decision variables including 33 integer and 61 continuous type variables. Simultaneously solving the subspaces leads to significant improvement in the fleet-level objective of the airline when compared to the previously developed sequential subspace decomposition approach.
AIRLINE NETWORK-AIRPLANE INTEGRATED OPTIMIZATION CONSIDERING MANUFACTURER'S PROGRAM COST
ICAS CONFERENCE, 2021
Aerial network routes and their flight frequencies are crucial for the strategic planning of airlines, Airlines must choose optimum airplane types to improve revenue and to reduce operating costs. In addition, aircraft manufacturers need to identify airplane configurations that better suit airline operations and establish list prices for their products as well as calculate the production and development costs of their products. To address these issues, the present study describes and applies a methodology to determine the optimal aerial transport network simultaneously with the identification of the optimum fleet for that network, namely, an integrated design. In the optimization simulations carried out in the present work, the objectives are the maximization of the operational cost of the airline and the minimization of the airplane fleet cost. Each fleet is composed of three types of airliners, selected according to their passenger capacity. Airplanes are designed with high-fidelity methods, realistic performance calculations and must obey a set of requirements, including some related to FAR 25 certification rules. Optimization for a Brazilian network considering 21 cities was carried out with the maximization of the network's daily profit and the minimization of the fleet acquisition cost. A comprehensive airplane manufacturer program cost estimation model was implemented, enabling the calculation of the net present value of a transport airplane program and financial parameters.
ICAS 2021, 2021
Aerial network routes and their flight frequencies are crucial for the strategic planning of airlines. Airlines must choose optimum airplane types to improve revenue and to reduce operating costs. In addition, aircraft manufacturers need to identify airplane configurations that better suit airline operations and establish list prices for their products as well as calculate the production and development costs of their products. To address these issues, the present study describes and applies a methodology to determine the optimal aerial transport network simultaneously with the identification of the optimum fleet for that network, namely, an integrated design. In the optimization simulations carried out in the present work, the objectives are the maximization of the operational cost of the airline and the minimization of the airplane fleet cost. Each fleet is composed of three types of airliners, selected according to their passenger capacity. Airplanes are designed with high-fidelity methods, realistic performance calculations and must obey a set of requirements, including some related to FAR 25 certification rules. Optimization for a Brazilian network considering 21 cities was carried out with the maximization of the network's daily profit and the minimization of the fleet acquisition cost. A comprehensive airplane manufacturer program cost estimation model was implemented, enabling the calculation of the net present value of a transport airplane program and financial parameters.
Transport, 2010
Regional aircraft are playing a significant role in airline operations. This paper considers the problem of selecting an appropriate aircraft from the airline fleet for optimal regional air travel realization. Complexity balance between air travel demand (passengers, goods) and the proposed aircraft capacity presents the priority in airline operations. A principal feature of the methodology considered in this paper is a multi attribute analysis of technological and operational aircraft characteristics (turboprop and turbojet). A comparison of the presented regional aircraft parameters is based on the following criteria: technological (aerodynamic efficiency, structural efficiency, fuel flow at the optional FL, cruise endurance and requested trip fuel for the fixed cruise range), operational (max range with max payload, ground efficiency (aircraft maintainability based on external dimensions) and climb capability. With the aim of defining aircraft rank, the TOPSIS (Technique for Orde...
Aircraft Selection Using Preference Optimization Programming (POP)
International Journal of Aerospace and Mechanical Engineering, 2022
A multiple-criteria decision support system is proposed for the best aircraft selection decision. Various strategic, economic, environmental, and risk-related factors can directly or indirectly influence this choice, and they should be taken into account in the decision-making process. The paper suggests a multiple-criteria analysis to aid in the airline management's decision-making process when choosing an appropriate aircraft. In terms of the suggested approach, an integrated entropic preference optimization programming (POP) for fleet modeling risk analysis is applied. The findings of the study of multiple criteria analysis indicate that the A321(neo) aircraft type is the best alternative in this particular optimization instance. The proposed methodology can be applied to other complex engineering problems involving multiple criteria analysis.