The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.F...The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature.展开更多
Multi-Source Information Fusion(MSIF),as a comprehensive interdisciplinary field based on modern information technology,has gained significant research value and extensive application prospects in various domains,attr...Multi-Source Information Fusion(MSIF),as a comprehensive interdisciplinary field based on modern information technology,has gained significant research value and extensive application prospects in various domains,attracting high attention and interest from scholars,engineering experts,and practitioners worldwide.Despite achieving fruitful results in both theoretical and applied aspects over the past five decades,there remains a lack of comprehensive and systematic review articles that provide an overview of recent development in MSIF.In light of this,this paper aims to assist researchers and individuals interested in gaining a quick understanding of the relevant theoretical techniques and development trends in MSIF,which conducts a statistical analysis of academic reports and related application achievements in the field of MSIF over the past two decades,and provides a brief overview of the relevant theories,methodologies,and application domains,as well as key issues and challenges currently faced.Finally,an analysis and outlook on the future development directions of MSIF are presented.展开更多
Piezoelectric resonant de-icing systems are attracting great interest.This paper aims to assess the implementation of these systems at the aircraft level.The article begins with the model to compute the power requirem...Piezoelectric resonant de-icing systems are attracting great interest.This paper aims to assess the implementation of these systems at the aircraft level.The article begins with the model to compute the power requirement of a piezoelectric resonant de-icing system sized from the prototype detailed in Part 1/2 of this article.Then the mass,drag,and fuel consumption of this system and the subcomponents needed for its implementation are assessed.The features of a piezoelectric resonant de-icing system are finally computed for aircraft similar to Airbus A320 aircraft and aircraft of different categories(Boeing 787,ATR 72 and TBM 900)and compared with the existing thermal and mechanical ice protection systems.A sensitivity analysis of the main key sizing parameters of the piezoelectric de-icing system is also performed to identify the main axes of improvement for this technology.The study shows the potential of such ice protection systems.In particular,for the realistic input parameters chosen in this work,the electro-mechanical solution can provide a 54% reduction in terms of mass and a 92% reduction in terms of power consumption for an A320 aircraft architecture,leading to a 74% decrease in the associated fuel consumption compared to the actual air bleed system.展开更多
In the theory of belief functions, the measure of uncertainty is an important concept, which is used for representing some types of uncertainty incorporated in bodies of evidence such as the discord and the non-specif...In the theory of belief functions, the measure of uncertainty is an important concept, which is used for representing some types of uncertainty incorporated in bodies of evidence such as the discord and the non-specificity. For the non-specificity part, some traditional measures use for reference the Hartley measure in classical set theory; other traditional measures use the simple and heuristic function for joint use of mass assignments and the cardinality of focal elements. In this paper, a new non-specificity measure is proposed using lengths of belief intervals, which represent the degree of imprecision. Therefore, it has more intuitive physical meaning. It can be proved that our new measure can be rewritten in a general form for the non-specificity. Our new measure is also proved to be a strict non-specificity measure with some desired properties. Numerical examples, simulations, the related analyses and proofs are provided to show the characteristics and good properties of the new non-specificity definition. An example of an application of the new non- specificity measure is also presented.展开更多
Dempster-Shafer evidence theory, also called the theory of belief function, is widely used for uncertainty modeling and reasoning. However, when the size and number of focal elements are large, the evidence combinatio...Dempster-Shafer evidence theory, also called the theory of belief function, is widely used for uncertainty modeling and reasoning. However, when the size and number of focal elements are large, the evidence combination will bring a high computational complexity. To address this issue,various methods have been proposed including the implementation of more efficient combination rules and the simplifications or approximations of Basic Belief Assignments(BBAs). In this paper,a novel principle for approximating a BBA into a simpler one is proposed, which is based on the degree of non-redundancy for focal elements. More non-redundant focal elements are kept in the approximation while more redundant focal elements in the original BBA are removed first. Three types of degree of non-redundancy are defined based on three different definitions of focal element distance, respectively. Two different implementations of this principle for BBA approximations are proposed including a batch and an iterative type. Examples, experiments, comparisons and related analyses are provided to validate proposed approximation approaches.展开更多
In the theory of belief functions,the evidence combination is a kind of decision-level information fusion.Given two or more Basic Belief Assignments(BBAs)originated from different information sources,the combination r...In the theory of belief functions,the evidence combination is a kind of decision-level information fusion.Given two or more Basic Belief Assignments(BBAs)originated from different information sources,the combination rule is used to combine them to expect a better decision result.When only a combined BBA is given and original BBAs are discarded,if one wants to analyze the difference between the information sources,evidence de-combination is needed to determine the original BBAs.Evidence de-combination can be considered as the inverse process of the information fusion.This paper focuses on such a defusion of information in the theory of belief functions.It is an under-determined problem if only the combined BBA is available.In this paper,two optimization-based approaches are proposed to de-combine a given BBA according to the criteria of divergence maximization and information maximization,respectively.The new proposed approaches can be used for two or more information sources.Some numerical examples and an example of application are provided to illustrate and validate our approaches.展开更多
The methods for combining multiple classifiers based on belief functions require to work with a common and complete(closed)Frame of Discernment(Fo D)on which the belief functions are defined before making their combin...The methods for combining multiple classifiers based on belief functions require to work with a common and complete(closed)Frame of Discernment(Fo D)on which the belief functions are defined before making their combination.This theoretical requirement is however difficult to satisfy in practice because some abnormal(or unknown)objects that do not belong to any predefined class of the Fo D can appear in real classification applications.The classifiers learnt using different attributes information can provide complementary knowledge which is very useful for making the classification but they are usually based on different Fo Ds.In order to clearly identify the specific class of the abnormal objects,we propose a new method for combination of classifiers working with incomplete frames of discernment,named CCIF for short.This is a progressive detection method that select and add the detected abnormal objects to the training data set.Because one pattern can be considered as an abnormal object by one classifier and be committed to a specific class by another one,a weighted evidence combination method is proposed to fuse the classification results of multiple classifiers.This new method offers the advantage to make a refined classification of abnormal objects,and to improve the classification accuracy thanks to the complementarity of the classifiers.Some experimental results are given to validate the effectiveness of the proposed method using real data sets.展开更多
This paper addresses the topic of the conceptual design of a regional aircraft with hybrid electric propulsion based on hydrogen fuel cells.It aims at providing an optimization-based method to design a hybrid propulsi...This paper addresses the topic of the conceptual design of a regional aircraft with hybrid electric propulsion based on hydrogen fuel cells.It aims at providing an optimization-based method to design a hybrid propulsive system comprising two power sources(jet fuel and hydrogen)for the generation of the required propulsive power and at studying the impact of fuel cell technologies on the aircraft performances.Indeed,by performing optimizations for two hybrid propulsive systems using either low temperature or high temperature proton-exchange membrane fuel cells,this study provides a preliminary assessment of the impact of the fuel cell operating temperature on the system design and the overall aircraft performance.First,this paper gives a description of the baseline turboprop regional aircraft with a focus on its high speed and low speed flight performances which will serve as requirements for the design of the hybrid aircraft.Then,the hybrid electric architecture and the sizing models of the propulsion system are presented.Finally,optimizations are performed to design two parallel hybrid propulsive systems based on different fuel cells technologies and aimed at minimizing the block fuel per passenger over a mission of 200 n mile.Results show how the proposed methodology and models lead to design two propulsive systems capable of reducing the fuel consumption per passenger by more than 30%compared to the baseline aircraft.The study also shows that the choice of fuel cell operating temperature has a first-order impact on the total mass.展开更多
Fiber reinforced titanium matrix composite is considered as a superior material for advanced lightweight aerospace application. Fiber/matrix interfacial reaction has a significant effect on the mechanical properties o...Fiber reinforced titanium matrix composite is considered as a superior material for advanced lightweight aerospace application. Fiber/matrix interfacial reaction has a significant effect on the mechanical properties of the composites. The SCS-6 SiC fiber reinforced Ti-6Al-4V matrix composite was prepared by foil-fiber-foil (FFF) method at ONERA, France. Stripe samples were cut from the as-consolidated composites and sealed in silicon carbide tube. One group of the samples were annealed for 58h at 550°C, 700°C, 850°C and 1000°C, the other group were annealed at 1000°C for 43h, 58h, 80h, lOOh, respectively. The interface investigation indicated that the connection between SiC fiber and the matrix is favorite in the composite. And the interface width for as-consolidated composite is only about 0.8um. The interface width increase with the prolong of annealing time and the increase of annealing temperature. But the increment for the latter is not as high as the former one, which means the annealing time may be the prior factor to influence the interface reaction. The interface width for the composite annealed at 1000°C for lOOh is about 20um. Interface composition of the composite detected by EDX is as follows: Ti 87.58 wt %, V 4.91 wt %, Al 4.06wt%, Si 3.45 wt %.展开更多
We briefly review the various proposed scenarios that may lead to nonthermal radio emissions from exoplanetary systems(planetary magnetospheres, magnetosphere-ionosphere and magnetospheresatellite coupling, and star-p...We briefly review the various proposed scenarios that may lead to nonthermal radio emissions from exoplanetary systems(planetary magnetospheres, magnetosphere-ionosphere and magnetospheresatellite coupling, and star-planet interactions), and the physical information that can be drawn from their detection. The latter scenario is especially favorable to the production of radio emission above 70 MHz. We summarize the results of past and recent radio searches, and then discuss FAST characteristics and observation strategy, including synergies. We emphasize the importance of polarization measurements and a high duty-cycle for the very weak targets that radio-exoplanets prove to be.展开更多
This article reviews the instrumental developments accomplished at ONERA in order to perform precise non-intrusive measurements of hypersonic flows using laser- and electron-beam-based optical techniques. Point line o...This article reviews the instrumental developments accomplished at ONERA in order to perform precise non-intrusive measurements of hypersonic flows using laser- and electron-beam-based optical techniques. Point line of sight and imaging measurements are possible. Point measurements have been implemented with Electron Beam Fluorescence （EBF） using detection of X-ray radiation and Coherent anti-Stokes Raman Scattering （CARS）. When spatial resolution is not required, diode laser absorption spectroscopy yields results integrated along a line. EBF imaging using a high energy pulsed electron gun is also quite promising. Rotational and vibrational populations of nitrogen and nitric oxide have been measured in various hypersonic hyperenthalpic facilities, as well as rotational state-resolved velocities in shocks and boundary layers.展开更多
The correction of buoyancy effects is tackled for particles moving close to a singular corner in creeping flow conditions.A few density-mismatched particle trajectories are used to reconstruct the dynamics of a neutra...The correction of buoyancy effects is tackled for particles moving close to a singular corner in creeping flow conditions.A few density-mismatched particle trajectories are used to reconstruct the dynamics of a neutrally-buoyant particle all over the target domain.We propose to take advantage of the dissipative dynamics of density-mismatched particles in order to probe the target domain.Thereafter,we retrieve the neutrally-buoyant particle flow all over the domain by reconstructing the phase space of the density-mismatched particulate flow and taking the limit of the particle-to-fluid density ratio tending to one.The robustness of such an approach is demonstrated by deliberately ill-conditioning the reconstruction operator.In fact,we show that our algorithm well performs even when we rely on qualitatively-different density-mismatched orbit topologies or on bundles of close trajectories rather than homogeneously distributed orbits.Potential applications to microfluidics and improvements of the proposed algorithm are finally discussed.展开更多
基金the French Defense Innovation Agency (AID)the French Procurement Agency for Armament (DGA)ONERA's scientific direction for funding and supporting the present work
文摘The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature.
基金co-supported by the National Natural Science Foundation of China(Nos.62233003 and 62073072)the Key Projects of Key R&D Program of Jiangsu Province,China(Nos.BE2020006 and BE2020006-1)the Shenzhen Science and Technology Program,China(Nos.JCYJ20210324132202005 and JCYJ20220818101206014).
文摘Multi-Source Information Fusion(MSIF),as a comprehensive interdisciplinary field based on modern information technology,has gained significant research value and extensive application prospects in various domains,attracting high attention and interest from scholars,engineering experts,and practitioners worldwide.Despite achieving fruitful results in both theoretical and applied aspects over the past five decades,there remains a lack of comprehensive and systematic review articles that provide an overview of recent development in MSIF.In light of this,this paper aims to assist researchers and individuals interested in gaining a quick understanding of the relevant theoretical techniques and development trends in MSIF,which conducts a statistical analysis of academic reports and related application achievements in the field of MSIF over the past two decades,and provides a brief overview of the relevant theories,methodologies,and application domains,as well as key issues and challenges currently faced.Finally,an analysis and outlook on the future development directions of MSIF are presented.
文摘Piezoelectric resonant de-icing systems are attracting great interest.This paper aims to assess the implementation of these systems at the aircraft level.The article begins with the model to compute the power requirement of a piezoelectric resonant de-icing system sized from the prototype detailed in Part 1/2 of this article.Then the mass,drag,and fuel consumption of this system and the subcomponents needed for its implementation are assessed.The features of a piezoelectric resonant de-icing system are finally computed for aircraft similar to Airbus A320 aircraft and aircraft of different categories(Boeing 787,ATR 72 and TBM 900)and compared with the existing thermal and mechanical ice protection systems.A sensitivity analysis of the main key sizing parameters of the piezoelectric de-icing system is also performed to identify the main axes of improvement for this technology.The study shows the potential of such ice protection systems.In particular,for the realistic input parameters chosen in this work,the electro-mechanical solution can provide a 54% reduction in terms of mass and a 92% reduction in terms of power consumption for an A320 aircraft architecture,leading to a 74% decrease in the associated fuel consumption compared to the actual air bleed system.
基金supported by the Grant for State Key Program for Basic Research of China(No.2013CB329405)National Natural Science Foundation of China(No.61573275)+3 种基金Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.61221063)Science and Technology Project of Shaanxi Province of China(No.2013KJXX-46)Specialized Research Fund for the Doctoral Program of Higher Education of China(20120201120036)Fundamental Research Funds for the Central Universities of China(No.xjj2014122)
文摘In the theory of belief functions, the measure of uncertainty is an important concept, which is used for representing some types of uncertainty incorporated in bodies of evidence such as the discord and the non-specificity. For the non-specificity part, some traditional measures use for reference the Hartley measure in classical set theory; other traditional measures use the simple and heuristic function for joint use of mass assignments and the cardinality of focal elements. In this paper, a new non-specificity measure is proposed using lengths of belief intervals, which represent the degree of imprecision. Therefore, it has more intuitive physical meaning. It can be proved that our new measure can be rewritten in a general form for the non-specificity. Our new measure is also proved to be a strict non-specificity measure with some desired properties. Numerical examples, simulations, the related analyses and proofs are provided to show the characteristics and good properties of the new non-specificity definition. An example of an application of the new non- specificity measure is also presented.
基金the National Natural Science Foundation of China (Nos. 61671370, 61573275)Postdoctoral Science Foundation of China (No. 2016M592790)+1 种基金Postdoctoral Science Research Foundation of Shaanxi Province, China (No. 2016BSHEDZZ46)Fundamental Research Funds for the Central Universities, China (No. xjj201066)
文摘Dempster-Shafer evidence theory, also called the theory of belief function, is widely used for uncertainty modeling and reasoning. However, when the size and number of focal elements are large, the evidence combination will bring a high computational complexity. To address this issue,various methods have been proposed including the implementation of more efficient combination rules and the simplifications or approximations of Basic Belief Assignments(BBAs). In this paper,a novel principle for approximating a BBA into a simpler one is proposed, which is based on the degree of non-redundancy for focal elements. More non-redundant focal elements are kept in the approximation while more redundant focal elements in the original BBA are removed first. Three types of degree of non-redundancy are defined based on three different definitions of focal element distance, respectively. Two different implementations of this principle for BBA approximations are proposed including a batch and an iterative type. Examples, experiments, comparisons and related analyses are provided to validate proposed approximation approaches.
基金supported by the National Natural Science Foundation of China(No.61671370)Project supported by joint foundation of X Lab–the 2~(nd)Academy of CASIC+1 种基金the Postdoctoral Science Foundation of China(No.2016M592790)the Postdoctoral Science Research Foundation of Shaanxi Province,China(No.2016BSHEDZZ46)。
文摘In the theory of belief functions,the evidence combination is a kind of decision-level information fusion.Given two or more Basic Belief Assignments(BBAs)originated from different information sources,the combination rule is used to combine them to expect a better decision result.When only a combined BBA is given and original BBAs are discarded,if one wants to analyze the difference between the information sources,evidence de-combination is needed to determine the original BBAs.Evidence de-combination can be considered as the inverse process of the information fusion.This paper focuses on such a defusion of information in the theory of belief functions.It is an under-determined problem if only the combined BBA is available.In this paper,two optimization-based approaches are proposed to de-combine a given BBA according to the criteria of divergence maximization and information maximization,respectively.The new proposed approaches can be used for two or more information sources.Some numerical examples and an example of application are provided to illustrate and validate our approaches.
基金partially supported by National Natural Science Foundation of China(Nos.U20B2067,61790552,61790554)Shaanxi Science Fund for Distinguished Young Scholars,China(No.2018JC-006)。
文摘The methods for combining multiple classifiers based on belief functions require to work with a common and complete(closed)Frame of Discernment(Fo D)on which the belief functions are defined before making their combination.This theoretical requirement is however difficult to satisfy in practice because some abnormal(or unknown)objects that do not belong to any predefined class of the Fo D can appear in real classification applications.The classifiers learnt using different attributes information can provide complementary knowledge which is very useful for making the classification but they are usually based on different Fo Ds.In order to clearly identify the specific class of the abnormal objects,we propose a new method for combination of classifiers working with incomplete frames of discernment,named CCIF for short.This is a progressive detection method that select and add the detected abnormal objects to the training data set.Because one pattern can be considered as an abnormal object by one classifier and be committed to a specific class by another one,a weighted evidence combination method is proposed to fuse the classification results of multiple classifiers.This new method offers the advantage to make a refined classification of abnormal objects,and to improve the classification accuracy thanks to the complementarity of the classifiers.Some experimental results are given to validate the effectiveness of the proposed method using real data sets.
基金ATR aircraft for the financial support of this research
文摘This paper addresses the topic of the conceptual design of a regional aircraft with hybrid electric propulsion based on hydrogen fuel cells.It aims at providing an optimization-based method to design a hybrid propulsive system comprising two power sources(jet fuel and hydrogen)for the generation of the required propulsive power and at studying the impact of fuel cell technologies on the aircraft performances.Indeed,by performing optimizations for two hybrid propulsive systems using either low temperature or high temperature proton-exchange membrane fuel cells,this study provides a preliminary assessment of the impact of the fuel cell operating temperature on the system design and the overall aircraft performance.First,this paper gives a description of the baseline turboprop regional aircraft with a focus on its high speed and low speed flight performances which will serve as requirements for the design of the hybrid aircraft.Then,the hybrid electric architecture and the sizing models of the propulsion system are presented.Finally,optimizations are performed to design two parallel hybrid propulsive systems based on different fuel cells technologies and aimed at minimizing the block fuel per passenger over a mission of 200 n mile.Results show how the proposed methodology and models lead to design two propulsive systems capable of reducing the fuel consumption per passenger by more than 30%compared to the baseline aircraft.The study also shows that the choice of fuel cell operating temperature has a first-order impact on the total mass.
文摘Fiber reinforced titanium matrix composite is considered as a superior material for advanced lightweight aerospace application. Fiber/matrix interfacial reaction has a significant effect on the mechanical properties of the composites. The SCS-6 SiC fiber reinforced Ti-6Al-4V matrix composite was prepared by foil-fiber-foil (FFF) method at ONERA, France. Stripe samples were cut from the as-consolidated composites and sealed in silicon carbide tube. One group of the samples were annealed for 58h at 550°C, 700°C, 850°C and 1000°C, the other group were annealed at 1000°C for 43h, 58h, 80h, lOOh, respectively. The interface investigation indicated that the connection between SiC fiber and the matrix is favorite in the composite. And the interface width for as-consolidated composite is only about 0.8um. The interface width increase with the prolong of annealing time and the increase of annealing temperature. But the increment for the latter is not as high as the former one, which means the annealing time may be the prior factor to influence the interface reaction. The interface width for the composite annealed at 1000°C for lOOh is about 20um. Interface composition of the composite detected by EDX is as follows: Ti 87.58 wt %, V 4.91 wt %, Al 4.06wt%, Si 3.45 wt %.
基金supported by the National Key R&D Program No. 2017YFA0402600the CAS International Partnership Program No. 14A11KYSB20160008the NSFC grant No. 11725313
文摘We briefly review the various proposed scenarios that may lead to nonthermal radio emissions from exoplanetary systems(planetary magnetospheres, magnetosphere-ionosphere and magnetospheresatellite coupling, and star-planet interactions), and the physical information that can be drawn from their detection. The latter scenario is especially favorable to the production of radio emission above 70 MHz. We summarize the results of past and recent radio searches, and then discuss FAST characteristics and observation strategy, including synergies. We emphasize the importance of polarization measurements and a high duty-cycle for the very weak targets that radio-exoplanets prove to be.
文摘This article reviews the instrumental developments accomplished at ONERA in order to perform precise non-intrusive measurements of hypersonic flows using laser- and electron-beam-based optical techniques. Point line of sight and imaging measurements are possible. Point measurements have been implemented with Electron Beam Fluorescence （EBF） using detection of X-ray radiation and Coherent anti-Stokes Raman Scattering （CARS）. When spatial resolution is not required, diode laser absorption spectroscopy yields results integrated along a line. EBF imaging using a high energy pulsed electron gun is also quite promising. Rotational and vibrational populations of nitrogen and nitric oxide have been measured in various hypersonic hyperenthalpic facilities, as well as rotational state-resolved velocities in shocks and boundary layers.
文摘The correction of buoyancy effects is tackled for particles moving close to a singular corner in creeping flow conditions.A few density-mismatched particle trajectories are used to reconstruct the dynamics of a neutrally-buoyant particle all over the target domain.We propose to take advantage of the dissipative dynamics of density-mismatched particles in order to probe the target domain.Thereafter,we retrieve the neutrally-buoyant particle flow all over the domain by reconstructing the phase space of the density-mismatched particulate flow and taking the limit of the particle-to-fluid density ratio tending to one.The robustness of such an approach is demonstrated by deliberately ill-conditioning the reconstruction operator.In fact,we show that our algorithm well performs even when we rely on qualitatively-different density-mismatched orbit topologies or on bundles of close trajectories rather than homogeneously distributed orbits.Potential applications to microfluidics and improvements of the proposed algorithm are finally discussed.
