Andrzej Majka

Multiple objective optimization of the power unit for a very light jet

Purpose – The purpose of this paper is to propose a solution of the engine bypass ratio choice problem of a very light jet (VLJ) class aircraft using the multiple objective optimization (MOO) method. Design/methodology/approach – The work focuses on the choice of one of the most essential parameters of the jet engine, that is its bypass ratio. The work presents the methodology of optimal designing using the multitask character of the matter which is based on the mathematical model of optimization in the concept of the set theory. To make an optimal choice of the chosen parameter, a complete computational model of an aircraftwas made (aerodynamic, power unit, performance and cost) and then the method that allows to choose the bypass ratio was selected, regardingmultiple estimating criteria of the obtained solutions. The presented method can be used at the concept design state for determining the chosen and most important technical parameters of the aircraft. Findings – The way to design a competing aircraf...

Take-off aided by magnetic levitation technology

Purpose – The purpose of the paper is to analyze changes in the selected characteristics of an aircraft aided by a ground-based system using magnetic levitation (MAGLEV) to support safe take-off. Design/methodology/approach – The analysis of the mass characteristics of the main aircraft units with conventional constructing solutions was carried out in this paper. It allowed determining the mass of these units and verifying the obtained results on the basis of the known examples. Thanks to such an approach it was possible to determine the mass of the aircraft modified for the requirements of the ground and on-board system for support of the aircraft safe take-off and landing (GABRIEL) system taking into account the change in the weights of the modified units (fuselage, wings, power unit, landing gear, etc.). The weight of the aircraft in its basic version was determined on the basis of the common knowledge and methods described in the scientific literature which are based on the statistical analysis. The w...

The Conceptual Design Study of a Patrol and Search and Rescue Wing-In-Ground Effect Craft

The Baltic Sea is a region with a high density of marine traffic. Being a state with a shoreline, Poland is obliged to supervise the maritime security. One of the means to guarantee a high level of security and minimize the number of accidents is to possess fast and efficient craft for search and rescue of people in danger at sea, monitoring and eliminating the risks of oil and chemical pollution of the sea environment. A WIG craft (Wing-In-Ground Effect Craft) has these characteristics as it uses the ground effect. There is a lack of information on using the WIG craft in search and rescue operations at sea (SAR). The aim of the paper is to present the results of the conceptual design study of a WIG craft intended to perform search and rescue tasks and patrol the sea and the coastal line.

The problem of choice of light passenger seaplane used for short - haul flights

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 amphibian aircraft with the use of small and medium airports and natural water landings. 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 amphibian aircrafts. They can use less busy airports and adjusted and re-qualified landing grounds as well as natural landing fields on water. The potential places for take-off and landing operations are port pools located on the coast of the sea, lake or big rivers. Operators and entrepreneurs interested in starting new seaplane businesses report about missing modern airplanes. The aim of the paper is to conduct comparative analysis of the characteristics of selected types of light amphibian aircrafts (existed and modified presently used land-based planes), helped to identify best fitted seaplane to estimated range of operation.

MINIMUM EMISSION UNCONVENTIONAL MAGLEV ASSISTED TAKE-OFF

Among the most important problems faced by the air transport today there can be mentioned some negative influences of aircraft and airports on the environment and the increasing costs of air transport. One of the possibilities to improve the situation is to work out innovative solutions aimed at decreasing of the aircraft pollution and improving the transport effectiveness. Among the most innovative ideas is the use of magnetic levitation (MAGLEV) to aid the take-off and landing of the transport aircraft. The “Integrated Ground and on-Board system for Support of the Aircraft Safe Take-off and Landing” – GABRIEL, deals with radically new integration of the MAGLEV technology into the air transportation system that contains aircraft, airport, air traffic control, authority, logistic and operational support, maintenance, etc. GABRIEL idea includes operation of the aircraft without the conventional undercarriage system and using the ground based power and supporting systems for take-offs and landings. In case of using the GABRIEL system as a catapult, the aircraft on the track must be accelerated to the speed permitting to reach the altitude of 300 m or more. Such take-off and climb results in minimum noise and minimal emission of substances harmful for the environment. After reaching the altitude of 300 m, the aircraft may follow its flight with using different flight strategies. Different conditions of the unconventional take-off needs to shape other way the trajectory of the initial stage of the aircraft flight after the lift-off. The aim of the present work was to determine the optimal conditions of the lift-off and the optimal trajectory of the initial climb minimizing the emission. Simplified realization of the RitzGalerkin method was used in this work, which uses an approximate solution to boundary value problems for determining the optimal flight trajectory.

Flight Loads of Mini UAV

Designing and building of the unmanned aircraft, especially light and ultra light vehicles, is mainly performed using the experience gained when constructing the flying models. There have not been uniform principles of building and exploiting of the mini and micro UAV (Unmanned Aerial Vehicle) in the form of regulations similar to those for manned airplanes. The unmanned vehicles of these classes in terms of their abilities and attractive price are more frequently exploited using the same air area as manned airplanes performing missions over the inhabited areas. An urgent necessity arises to work out the norms of flight suitability of the mini and micro unmanned aerial vehicles. The work contains the analysis of suitability of the current aviation regulations to determine the requirements for the mini unmanned vehicles. The work concentrates on the phenomenon of determining the symmetrical loads from the maneuvers and the turbulence atmosphere. The result of this analysis is the Limit Maneuver Envelope, Limit Gust Envelope and Limit Combined Envelope for mini UAV. The analyzed flight states allowed selecting the so called design cases which can become a basis for determining the norms of loading of mini unmanned aerial vehicles which can constitute the beginning of the regulations for building of the unmanned aerial vehicles of this class.

THE MULTI-OBJECTIVE OPTIMIZATION OF THE AIR TRANSPORTATION FLEET STRUCTURE

One of the most important factors in the development of modern civilization has become the increase in the significance of mobile and fast means of transportation of people and cargo. Aircraft as the fastest available means in the entire transportation system is the basis in places where the distance in the transportation of people is long and the travel time is short. The present work focuses on passenger transport in the European area using light transport aircraft, which may complement existing air transport and can become a real alternative to those who travel by other means of transport. The system of local transportation will become competitive in relation to other means of transport and will find its place on the market only when it has the highest indicators of efficiency. It can be reached by optimally obtaining passenger aircrafts fleet structure performing transportation tasks and optimizing its functioning. One of the basic problems is the rational selection and use of aircrafts, i.e. the minimization of their quantity while at the same time guarantee complete performance of transporting tasks. The selection of the best method of using the means of transport is connected with a large number of alternative variants, which makes it necessary to use special methods of searching for optimal solutions. The quality of the aircraft fleet should be estimated on the basis of several criteria when taking into account the difference in performing tasks. The way to design a competing aircraft fleet is to choose its characteristics by using advanced methods of multiple objective optimization. This work presents the methodology of the optimal designing of the aircraft fleet using the multitask character of the matter which is based on multiple objective mathematical programming in the concept of the set theory.

Evaluation of the required ground power of a ground - based system for support of the aircraft safe take - off and landing

Among the most important problems faced by the air transport today there can be mentioned some negative influences of aircraft and airports on the environment and the increasing costs of air transport. One of the possibilities to improve the situation is to work out innovative solutions aimed at decreasing of the aircraft pollution and improving the transport effectiveness. Among the most innovative ideas is the use of magnetic levitation to aid the take-off and landing of the transport aircraft. The use of the aiding system will bring a lot of benefits, however, regarding its innovative character and the problems connected with it, the idea can have been realized in a couple of years or even decades. The aim of this work was to carry out the analysis of the change to the required thrust of the transport aircraft in the take-off, landing and cruise using the system of magnetic levitation. Magnetic levitation or magnetic suspension is a method by which a body floats due to a special quality of magnets. The generated electromagnetic force is used to balance the weight of the object. The current work describes the ways of determining the weights of the main systems of the aircraft with classical construction solutions where the weight of the whole aircraft is estimated on the basis of the statistical methods. It allows determining the weights of all main systems of the aircraft and verifying the results using the known examples. Thanks to this approach, it could be possible to determine the modified aircraft weight more thoroughly, adding the changes in weights of the modified systems.

The Analysis of the Influence of the Design Parameters on the Performance Characteristics of a Mini UAV

In the conditions of the growing intensity of the UAV usage one of the most important problems is the improvement of their technical and performance effectiveness. It can be achieved applying the advanced methods of optimal designing. Apart from constructing an appropriate calculation model of the UAV, such an approach requires separating a group of decisive parameters, determining the limits and choosing the criterion of optimization. The precision and the range of use of the constructed calculation model must be adequate to a particular task allowing the optimal choice of characteristics of an aerial vehicle. Selection of the design parameters requires answering the question which technical parameters (geometrical, constructional etc.) of the UAV influence the performance characteristics of the aircraft positively. Analyzing the gradients of the performance characteristics change depending on the change in the design parameters, it is possible to determine the level of precision when determining the values and formulating the condition of finishing the optimization calculations. The aim of this work was to analyze the influence of selected design parameters on the performance characteristics of a mini UAV.

The green trajectory of an aircraft aided during take-off by ground-based system using magnetic levitation technology

Purpose The purpose of the paper is to determine the optimal conditions of the take-off and the optimal trajectory of the initial climb minimizing the fuel consumption of the aircraft aided in the ground phase of the take-off by the system using the MAGLEV technology. Design/methodology/approach The study concerned determining the optimal trajectory of the initial phase of the transport aircraft climb aided in the phase of acceleration by the system using the magnetic levitation phenomenon. The simplified algorithm of the Ritz–Galerkin method was used in this work which uses an approximate solution to boundary value problems for determining the optimal flight trajectory. It uses the method of approximation of the flight path by the third-degree polynomial. The method allows determining the optimal trajectory of the flight satisfying the initial/final conditions and control functions and path constrains for an aircraft. General stating of the task supposes determining the optimal trajectory of movement of a flying vehicle described by the system of ordinary differential equations. The resulting sparse non-linear programming problem has been solved using own elaborated software. The typical profiles computation has been performed with a tool combining three degree of freedom flight dynamics differential equations with procedure-oriented flight control. Findings Different conditions of the take-off of the aircraft aided by the ground system using the MAGLEV technology give possibilities to shape the trajectory of the initial stage of the aircraft climb after the lift-off to decrease the negative influence on the environment. Optimization of the departure trajectory minimizing fuel consumption or noise emissions can become the basis for working out new procedures for a new kind of take-off modified in relation to the optimal solution which will increase the safety of this segment of the flight. Research limitations/implications The analysis was carried out only for the departure trajectory to minimize fuel consumption, without investigation of possibilities of noise reduction. The trajectory guaranteeing minimization of the fuel consumption would also give a solution characterized by minimal emission of substances harmful for the environment. Practical implications Application of the innovatory solution of aided take-off is connected with modification of the climbing procedures after the take-off to minimize the negative effect of the aircraft on the surrounded environment. The results can become the basis for working out new procedures which will minimize negative influence to the natural environment in the vicinity of the airports of air transport and increase safety of the take-off and landing operations. Originality/value Innovative method of the take-off implies new shape of the trajectory. The study presents the results of the climb trajectory optimization of the aircraft supported at the ground stage by the technology using magnetic levitation phenomenon.