Pub Date : 2022-06-10DOI: 10.3846/aviation.2022.16869
Farid Saifutdinov, I. Jackson, J. Tolujevs
The paper discusses the prospects for the development and implementation of centralized ground traffic control systems at airports. The automatic control system can only work if there is accurate data on the location of mobile objects, which include both vehicles involved in the maintenance of aircraft and the aircraft themselves. In order to develop and test software for any specific centralized control system, the emulation mode should be used, in which the simulation model of the airport transport network works in conjunction with the real control software. In this case, one of the main functions of the simulation model is the generation of data streams that appropriately reflect the processes of movement of objects in the transport network of a specific airport. The paper describes a universal simulation program that allows one to simulate precisely described scenarios for the process in a transport network, which necessitates decision-making at the level of a centralized control system. The movement of objects in the model is accompanied by the recording of their coordinates in the Digital Twin. In this way, real streams of measurement data from various systems for determining the position of moving objects are modeled and stored.
{"title":"AN EMULATION ORIENTED METHOD AND TOOL FOR TEST OF GROUND TRAFFIC CONTROL SYSTEMS AT AIRPORTS","authors":"Farid Saifutdinov, I. Jackson, J. Tolujevs","doi":"10.3846/aviation.2022.16869","DOIUrl":"https://doi.org/10.3846/aviation.2022.16869","url":null,"abstract":"The paper discusses the prospects for the development and implementation of centralized ground traffic control systems at airports. The automatic control system can only work if there is accurate data on the location of mobile objects, which include both vehicles involved in the maintenance of aircraft and the aircraft themselves. In order to develop and test software for any specific centralized control system, the emulation mode should be used, in which the simulation model of the airport transport network works in conjunction with the real control software. In this case, one of the main functions of the simulation model is the generation of data streams that appropriately reflect the processes of movement of objects in the transport network of a specific airport. The paper describes a universal simulation program that allows one to simulate precisely described scenarios for the process in a transport network, which necessitates decision-making at the level of a centralized control system. The movement of objects in the model is accompanied by the recording of their coordinates in the Digital Twin. In this way, real streams of measurement data from various systems for determining the position of moving objects are modeled and stored.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43350237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.3846/aviation.2022.16886
M. Čížek, V. Klír, P. Steinbauer, T. Vampola
This article presents currently obtained results from CFD analysis of the labyrinth seals of an aircraft turbine engine. The process of describing a geometry, grid for numerical calculation and boundary conditions are described. Numerical simulations were performed for the assumed boundary conditions. The presented results show total temperature differences in labyrinth seals compared to published results. An experimental verification of the CFD analysis was also performed to clarify the numerical simulation results. It was based on the labyrinth seal measurement stand. The final part of this study is dedicated to the discussion and the following possible activities on this topic.
{"title":"LABYRINTH SEAL CFD CALCULATION AND TEMPERATURE MEASUREMENT INVESTIGATION","authors":"M. Čížek, V. Klír, P. Steinbauer, T. Vampola","doi":"10.3846/aviation.2022.16886","DOIUrl":"https://doi.org/10.3846/aviation.2022.16886","url":null,"abstract":"This article presents currently obtained results from CFD analysis of the labyrinth seals of an aircraft turbine engine. The process of describing a geometry, grid for numerical calculation and boundary conditions are described. Numerical simulations were performed for the assumed boundary conditions. The presented results show total temperature differences in labyrinth seals compared to published results. An experimental verification of the CFD analysis was also performed to clarify the numerical simulation results. It was based on the labyrinth seal measurement stand. The final part of this study is dedicated to the discussion and the following possible activities on this topic.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49173866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-30DOI: 10.3846/aviation.2022.16920
A. Goncharenko
The paper considers theoretical preparation for the aircraft pre-air-trial. The construction of some mathematical models of a horizontal flight is based upon the material system of variable mass motion. Optimal speed of horizontal flight is obtained as a function of variable mass. This speed is a solution (extremal) of the objective functional of the flying apparatus horizontal flight endurance. The solution delivers maximal value to the objective functional. The main significant assumptions made at the problem setting are: the rate of the aircraft horizontal flight speed change is negligibly small, flying object engines thrust has the horizontal component only, the dependence between aerodynamic coefficients is simplified in approximation with a quadratic parabola; the data used in simulation are abstract, although plausible. It was shown that in spite of the speed changes during the studied flight, the rate of that change plays an unimportant role for the considered case; therefore, such supposition of the rate neglecting is properly grounded. The derived equations allow taking into account the rate when it is the matter of importance. Since the presented study is the simplified one, the obtained results could be considered as some reference values to be tested and possibly approached to.
{"title":"MODELLING AN AIRCRAFT MAXIMUM ENDURANCE HORIZONTAL FLIGHT FOR AIR TRIALS","authors":"A. Goncharenko","doi":"10.3846/aviation.2022.16920","DOIUrl":"https://doi.org/10.3846/aviation.2022.16920","url":null,"abstract":"The paper considers theoretical preparation for the aircraft pre-air-trial. The construction of some mathematical models of a horizontal flight is based upon the material system of variable mass motion. Optimal speed of horizontal flight is obtained as a function of variable mass. This speed is a solution (extremal) of the objective functional of the flying apparatus horizontal flight endurance. The solution delivers maximal value to the objective functional. The main significant assumptions made at the problem setting are: the rate of the aircraft horizontal flight speed change is negligibly small, flying object engines thrust has the horizontal component only, the dependence between aerodynamic coefficients is simplified in approximation with a quadratic parabola; the data used in simulation are abstract, although plausible. It was shown that in spite of the speed changes during the studied flight, the rate of that change plays an unimportant role for the considered case; therefore, such supposition of the rate neglecting is properly grounded. The derived equations allow taking into account the rate when it is the matter of importance. Since the presented study is the simplified one, the obtained results could be considered as some reference values to be tested and possibly approached to.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46120240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-30DOI: 10.3846/aviation.2022.16878
Ibrahim H. Cihan
This paper presents a comparison of fuel-optimal and shortest paths of an unmanned combat aerial vehicle (UCAV) with obstacle avoidance. A nonlinear constrained optimization algorithm is applied to obtain the optimal paths. An initial value problem (IVP) and an inverse-dynamics approach are used separately to determine optimal paths for various scenarios and in order to reduce computation time. While inputs of the optimization algorithm are discrete control variables in the IVP method, discrete state variables are used as inputs in the inverse-dynamics method. The minimized path segments of the geometrical model provide an initial estimation of the heading angle for the aircraft flight mechanics model. The number of variables used by the optimization algorithm has a direct effect upon the optimal accuracy; however, the computation time is inversely proportional to the number of the variables. Simulation results demonstrate that the proposed IVP method effectively converges to optimal solutions.
{"title":"COMPARING FUEL-OPTIMAL AND SHORTEST PATHS WITH OBSTACLE AVOIDANCE","authors":"Ibrahim H. Cihan","doi":"10.3846/aviation.2022.16878","DOIUrl":"https://doi.org/10.3846/aviation.2022.16878","url":null,"abstract":"This paper presents a comparison of fuel-optimal and shortest paths of an unmanned combat aerial vehicle (UCAV) with obstacle avoidance. A nonlinear constrained optimization algorithm is applied to obtain the optimal paths. An initial value problem (IVP) and an inverse-dynamics approach are used separately to determine optimal paths for various scenarios and in order to reduce computation time. While inputs of the optimization algorithm are discrete control variables in the IVP method, discrete state variables are used as inputs in the inverse-dynamics method. The minimized path segments of the geometrical model provide an initial estimation of the heading angle for the aircraft flight mechanics model. The number of variables used by the optimization algorithm has a direct effect upon the optimal accuracy; however, the computation time is inversely proportional to the number of the variables. Simulation results demonstrate that the proposed IVP method effectively converges to optimal solutions.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44806850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-26DOI: 10.3846/aviation.2022.16808
Marta Galant-Gołębiewska, Barbara Mika, Marta Maciejewska
The widely held thesis is that the profession of pilot is one of the most difficult jobs to do. The task of the article was to analyse whether and how the difficulty of the performed task affects the pilot’s workload during the flight. The research was carried out using a flight simulator. During the simulator tests, the cognitive load measurements represented by the change in pilot pulse and concentration were used. A finger pulse oximeter was used for the first purpose. The second device was Mindwave Mobile which allows to measure level of pilot’s concentration and relaxation. The NASA-TLX questionnaire is used as a subjective method of operator’s workload assessment. The examined person assesses the level of his/her load, using six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration level. Five research hypotheses were put forward and verified by the Friedman test. It has been shown that the level of difficulty of individual stages of the study is appropriately differentiated by pulse, concentration, relaxation, and subjective assessment of the respondents’ workload. It has been proved that pulse measurement, concentration, and relaxation levels, as well as subjective assessment of load levels, can be successfully used to assess the psychophysical condition of the operator.
{"title":"ANALYSIS OF THE IMPACT OF TASK DIFFICULTY ON THE OPERATORʾS WORKLOAD LEVEL","authors":"Marta Galant-Gołębiewska, Barbara Mika, Marta Maciejewska","doi":"10.3846/aviation.2022.16808","DOIUrl":"https://doi.org/10.3846/aviation.2022.16808","url":null,"abstract":"The widely held thesis is that the profession of pilot is one of the most difficult jobs to do. The task of the article was to analyse whether and how the difficulty of the performed task affects the pilot’s workload during the flight. The research was carried out using a flight simulator. During the simulator tests, the cognitive load measurements represented by the change in pilot pulse and concentration were used. A finger pulse oximeter was used for the first purpose. The second device was Mindwave Mobile which allows to measure level of pilot’s concentration and relaxation. The NASA-TLX questionnaire is used as a subjective method of operator’s workload assessment. The examined person assesses the level of his/her load, using six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration level. Five research hypotheses were put forward and verified by the Friedman test. It has been shown that the level of difficulty of individual stages of the study is appropriately differentiated by pulse, concentration, relaxation, and subjective assessment of the respondents’ workload. It has been proved that pulse measurement, concentration, and relaxation levels, as well as subjective assessment of load levels, can be successfully used to assess the psychophysical condition of the operator.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44835091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-05DOI: 10.3846/aviation.2022.15963
Filip Sklenář, Jiří Matějů
Problem of pitot tube blocking is persistent because even in the recent past there have been several accidents based on inaccurate information from air speed indicators. This problem was caused by a partial or complete blockage of the total pressure probes. Certain principles of blocking detection are well known. This article describes research into another principle of the gradual blocking detection of the pitot tube with drain holes. Pitot tubes with different blockage ratios were made and tested. A gradual blocking curve was described. The independence of velocity magnitude for the investigated airspeeds was found. This research shows that the drain hole design can be useful for a pitot tube blockage detection. The principle is based on another pitot tube with a larger drain hole area. Airspeed error due to gradual blocking grows faster on the other pitot tube. Gradual blocking of both pitot tubes results in a difference in indicated airspeeds, even at constant speed flight and before full blockage. This airspeed difference can warn a pilot and gives him or her a valuable time to use emergency procedures.
{"title":"INDICATED AIRSPEED ERROR DUE TO GRADUAL BLOCKING OF PITOT TUBE WITH DRAIN HOLE","authors":"Filip Sklenář, Jiří Matějů","doi":"10.3846/aviation.2022.15963","DOIUrl":"https://doi.org/10.3846/aviation.2022.15963","url":null,"abstract":"Problem of pitot tube blocking is persistent because even in the recent past there have been several accidents based on inaccurate information from air speed indicators. This problem was caused by a partial or complete blockage of the total pressure probes. Certain principles of blocking detection are well known. This article describes research into another principle of the gradual blocking detection of the pitot tube with drain holes. Pitot tubes with different blockage ratios were made and tested. A gradual blocking curve was described. The independence of velocity magnitude for the investigated airspeeds was found. This research shows that the drain hole design can be useful for a pitot tube blockage detection. The principle is based on another pitot tube with a larger drain hole area. Airspeed error due to gradual blocking grows faster on the other pitot tube. Gradual blocking of both pitot tubes results in a difference in indicated airspeeds, even at constant speed flight and before full blockage. This airspeed difference can warn a pilot and gives him or her a valuable time to use emergency procedures.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69990813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-31DOI: 10.3846/aviation.2022.16570
A. Gharib, M. Goharimanesh, A. Koochi, M. Gharib
This paper aims to design a reliable filter that can transform the actual motion of a flight simulator maneuver into a logical and understandable movement for its workspace. Motion cueing algorithms are used in scaling maneuvers to improve the user’s perception of real-world motion. As a unique algorithm, the washout-filter algorithm reduces the real motions where the user cannot understand the difference between the actual and simulated maneuvers. To design a proper washout filter, first, apply the inner ear model where humans can feel the motion to design a proper filter. The Otolith and semicircular systems were represented by two parts in this model. Second, an evolutionary theory based on a genetic algorithm is used to design a structure that minimizes human perception error and workspace boundaries. The issue is determining the coefficients in the model in order to create a high-performance flight simulator. The filtering algorithm, based upon the human vestibular model, compares human perception with flight simulator motion knowledge. The findings demonstrate an objective function that minimizes user perception error, and the flight simulator motion range can prepare a reliable washout filter for motion cueing.
{"title":"DESIGNING AN EVOLUTIONARY OPTIMAL WASHOUT FILTER BASED ON GENETIC ALGORITHM","authors":"A. Gharib, M. Goharimanesh, A. Koochi, M. Gharib","doi":"10.3846/aviation.2022.16570","DOIUrl":"https://doi.org/10.3846/aviation.2022.16570","url":null,"abstract":"This paper aims to design a reliable filter that can transform the actual motion of a flight simulator maneuver into a logical and understandable movement for its workspace. Motion cueing algorithms are used in scaling maneuvers to improve the user’s perception of real-world motion. As a unique algorithm, the washout-filter algorithm reduces the real motions where the user cannot understand the difference between the actual and simulated maneuvers. To design a proper washout filter, first, apply the inner ear model where humans can feel the motion to design a proper filter. The Otolith and semicircular systems were represented by two parts in this model. Second, an evolutionary theory based on a genetic algorithm is used to design a structure that minimizes human perception error and workspace boundaries. The issue is determining the coefficients in the model in order to create a high-performance flight simulator. The filtering algorithm, based upon the human vestibular model, compares human perception with flight simulator motion knowledge. The findings demonstrate an objective function that minimizes user perception error, and the flight simulator motion range can prepare a reliable washout filter for motion cueing.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48984204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-30DOI: 10.3846/aviation.2022.16519
S. Ganesan, B. Esakki, S. Mathiyazhagan, Vikram Pandimuthu
This article’s incitement interprets Unmanned Amphibious Aerial Vehicle (UAAV)’s conceptual design process in a systematic approach. The UAAV is conceptualised to be an ideal tool for limnologists in water quality assessment. Integration of hovercraft with the multi-rotor system helps collect water samples from remote and inaccessible water bodies. The UAAV flies in multi-rotor mode, subsequently land and glide along the water surface in hovercraft mode. The new and unconventional vehicle configuration makes the conceptual stage a challenging one in the design process. To overcome the challenges and strapped configuration of vehicle design, the Authors used a systematic approach of scenario-based design, morphological matrix, and Pugh’s method in the design process of the “Pahl & Beitz” model to retrieve the best possible UAAV design. The conglomerate design of UAAV is evaluated for its design requirements, and the computational analysis is performed to examine the mechanical strength and flow characteristics of UAAV. The experimental prototype of UAAV demonstrates the competence of flying in the air and hovering in water through field trials.
{"title":"DESIGN CONCEPTION AND EVALUATION OF AN UNMANNED AMPHIBIOUS AERIAL VEHICLE USING SYSTEMATIC APPROACH","authors":"S. Ganesan, B. Esakki, S. Mathiyazhagan, Vikram Pandimuthu","doi":"10.3846/aviation.2022.16519","DOIUrl":"https://doi.org/10.3846/aviation.2022.16519","url":null,"abstract":"This article’s incitement interprets Unmanned Amphibious Aerial Vehicle (UAAV)’s conceptual design process in a systematic approach. The UAAV is conceptualised to be an ideal tool for limnologists in water quality assessment. Integration of hovercraft with the multi-rotor system helps collect water samples from remote and inaccessible water bodies. The UAAV flies in multi-rotor mode, subsequently land and glide along the water surface in hovercraft mode. The new and unconventional vehicle configuration makes the conceptual stage a challenging one in the design process. To overcome the challenges and strapped configuration of vehicle design, the Authors used a systematic approach of scenario-based design, morphological matrix, and Pugh’s method in the design process of the “Pahl & Beitz” model to retrieve the best possible UAAV design. The conglomerate design of UAAV is evaluated for its design requirements, and the computational analysis is performed to examine the mechanical strength and flow characteristics of UAAV. The experimental prototype of UAAV demonstrates the competence of flying in the air and hovering in water through field trials.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48854032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-25DOI: 10.3846/aviation.2022.16471
Hatice Cansu Ayaz Ümütlü, Z. Kıral
There are different types of airfoil used in many applications such as energy production, aerospace, mixing of fluid products. Design optimization studies are still being carried out on the airfoil type structures. The airfoil section is the most important factor affecting the quality and efficiency of the performed work. The aim of this study is the optimization of the airfoil shape to generate more lift than the original airfoil shape creates. For this purpose, Bézier curves are used to generate the airfoil polar points, XFOIL is used as a flow solver and MATLAB is used to create optimization codes using the genetic algorithm. The results show that the created optimal airfoil shape produces more lift than the original airfoil shape. In this study, design optimization studies are supported by flow analysis using ANSYS Fluent.
{"title":"AIRFOIL SHAPE OPTIMIZATION USING BÉZIER CURVE AND GENETIC ALGORITHM","authors":"Hatice Cansu Ayaz Ümütlü, Z. Kıral","doi":"10.3846/aviation.2022.16471","DOIUrl":"https://doi.org/10.3846/aviation.2022.16471","url":null,"abstract":"There are different types of airfoil used in many applications such as energy production, aerospace, mixing of fluid products. Design optimization studies are still being carried out on the airfoil type structures. The airfoil section is the most important factor affecting the quality and efficiency of the performed work. The aim of this study is the optimization of the airfoil shape to generate more lift than the original airfoil shape creates. For this purpose, Bézier curves are used to generate the airfoil polar points, XFOIL is used as a flow solver and MATLAB is used to create optimization codes using the genetic algorithm. The results show that the created optimal airfoil shape produces more lift than the original airfoil shape. In this study, design optimization studies are supported by flow analysis using ANSYS Fluent.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46159989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-23DOI: 10.3846/aviation.2022.16621
N. Daidzic
A mathematical model of free balloon launches in windy conditions is based on the conservation of the linear momentum in horizontal and vertical axes. Linear momentum conservation equations are represented by a set of four nonlinear first-order ODEs. Some ODEs were solved analytically, while the nonlinear Riccati ODE with variable coefficients for the vertical acceleration was solved using numerical ODE solvers. Transient aerodynamic lift and horizontal drag are caused by the slip flow over the balloon envelope. It takes free balloon ten half times to reach 90.9% of the wind velocity in a step function response. A launch condition was developed in terms of the minimum required envelope temperature for which the net aerostatic lift overcomes inert weight of a balloon. Perturbation analysis was used to explore changes in the net aerostatic lift. Simulations were performed to cases with and without envelope distortion and enhanced cooling due to forced convection. Since all balloon takeoffs are performed downwind, obstacle clearance becomes an issue due to rapid loss of aerodynamic lift. Balloons may stop climbing and even start descending shortly after liftoff despite intense heating representing real hazard.
{"title":"MATHEMATICAL MODEL AND SIMULATION OF FREE BALLOON LIFTOFF IN THE PRESENCE OF SURFACE WINDS","authors":"N. Daidzic","doi":"10.3846/aviation.2022.16621","DOIUrl":"https://doi.org/10.3846/aviation.2022.16621","url":null,"abstract":"A mathematical model of free balloon launches in windy conditions is based on the conservation of the linear momentum in horizontal and vertical axes. Linear momentum conservation equations are represented by a set of four nonlinear first-order ODEs. Some ODEs were solved analytically, while the nonlinear Riccati ODE with variable coefficients for the vertical acceleration was solved using numerical ODE solvers. Transient aerodynamic lift and horizontal drag are caused by the slip flow over the balloon envelope. It takes free balloon ten half times to reach 90.9% of the wind velocity in a step function response. A launch condition was developed in terms of the minimum required envelope temperature for which the net aerostatic lift overcomes inert weight of a balloon. Perturbation analysis was used to explore changes in the net aerostatic lift. Simulations were performed to cases with and without envelope distortion and enhanced cooling due to forced convection. Since all balloon takeoffs are performed downwind, obstacle clearance becomes an issue due to rapid loss of aerodynamic lift. Balloons may stop climbing and even start descending shortly after liftoff despite intense heating representing real hazard.","PeriodicalId":51910,"journal":{"name":"Aviation","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42960888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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