In this paper,two typical stealth aircraft concepts（wing fuselage blended and flyingwing） were designed.Then three gradually changed surface distribution models with the same planform for each concept were created.B...In this paper,two typical stealth aircraft concepts（wing fuselage blended and flyingwing） were designed.Then three gradually changed surface distribution models with the same planform for each concept were created.Based on the multilevel fast multipole algorithm（MLFMA）,the vertical polarization transmitting/vertical polarization receiving（VV） and horizontal polarization transmitting/horizontal polarization receiving（HH） radar cross section（RCS） characteristics were simulated with five frequencies between 0.1 and 1.0 GHz.The influences and mechanisms of aircraft surface distribution on electromagnetic scattering characteristics were investigated.The results show that for the wing fuselage blended concept,the W RCS of this frequency range is higher than the HH RCS in most cases,while it is just the opposite for the flying-wing concept.As for the two aircraft concepts,the RCS levels of HH and W both decrease with the frequency increasing,but the HH RCS has a faster downward trend.The surface distribution has little influence on HH RCS characteristics.On the contrary,it has a significant impact on W RCS characteristics,and the amplitude of the VV RCS increases with the surface thickness.展开更多
In this study,a process for establishing design requirements and selecting alternative configurations for the conceptual phase of aircraft design has been proposed.The proposed process uses system-engineering-based re...In this study,a process for establishing design requirements and selecting alternative configurations for the conceptual phase of aircraft design has been proposed.The proposed process uses system-engineering-based requirement-analysis techniques such as objective tree,analytic hierarchy process,and quality function deployment to establish logical and quantitative standards.Moreover,in order to perform a logical selection of alternative aircraft configurations,it uses advanced decision-making methods such as morphological matrix and technique for order preference by similarity to the ideal solution.In addition,a preliminary sizing tool has been developed to check the feasibility of the established performance requirements and to evaluate the flight performance of the selected configurations.The present process has been applied for a two-seater very light aircraft（VLA）,resulting in a set of tentative design requirements and two families of VLA configurations：a high-wing configuration and a low-wing configuration.The resulting set of design requirements consists of three categories：customer requirements,certification requirements,and performance requirements.The performance requirements include two mission requirements for the flight range and the endurance by reflecting the customer requirements.The flight performances of the two configuration families were evaluated using the sizing tool developed and the low-wing configuration with conventional tails was selected as the best baseline configuration for the VLA.展开更多
文摘In this paper,two typical stealth aircraft concepts（wing fuselage blended and flyingwing） were designed.Then three gradually changed surface distribution models with the same planform for each concept were created.Based on the multilevel fast multipole algorithm（MLFMA）,the vertical polarization transmitting/vertical polarization receiving（VV） and horizontal polarization transmitting/horizontal polarization receiving（HH） radar cross section（RCS） characteristics were simulated with five frequencies between 0.1 and 1.0 GHz.The influences and mechanisms of aircraft surface distribution on electromagnetic scattering characteristics were investigated.The results show that for the wing fuselage blended concept,the W RCS of this frequency range is higher than the HH RCS in most cases,while it is just the opposite for the flying-wing concept.As for the two aircraft concepts,the RCS levels of HH and W both decrease with the frequency increasing,but the HH RCS has a faster downward trend.The surface distribution has little influence on HH RCS characteristics.On the contrary,it has a significant impact on W RCS characteristics,and the amplitude of the VV RCS increases with the surface thickness.
基金the support provided for this research by a grant(No.1615001723) from the Light Aircraft Development Program funded by the Ministry of Land,Infrastructure and Transport of the Korean governmentthe National Research Foundation of Korea(No.NRF-2014R1A2A2A01003833) funded by the Korean government(MSIP)
文摘In this study,a process for establishing design requirements and selecting alternative configurations for the conceptual phase of aircraft design has been proposed.The proposed process uses system-engineering-based requirement-analysis techniques such as objective tree,analytic hierarchy process,and quality function deployment to establish logical and quantitative standards.Moreover,in order to perform a logical selection of alternative aircraft configurations,it uses advanced decision-making methods such as morphological matrix and technique for order preference by similarity to the ideal solution.In addition,a preliminary sizing tool has been developed to check the feasibility of the established performance requirements and to evaluate the flight performance of the selected configurations.The present process has been applied for a two-seater very light aircraft（VLA）,resulting in a set of tentative design requirements and two families of VLA configurations：a high-wing configuration and a low-wing configuration.The resulting set of design requirements consists of three categories：customer requirements,certification requirements,and performance requirements.The performance requirements include two mission requirements for the flight range and the endurance by reflecting the customer requirements.The flight performances of the two configuration families were evaluated using the sizing tool developed and the low-wing configuration with conventional tails was selected as the best baseline configuration for the VLA.
