To identify the unsteady°uid dynamic model for a solid moving in the°uid,a new identication method that operates in the continuous time domain is proposed.It is illustrated that this new identication method ...To identify the unsteady°uid dynamic model for a solid moving in the°uid,a new identication method that operates in the continuous time domain is proposed.It is illustrated that this new identication method is more accurate and appropriate for identifying unsteady°uid dynamic model in incompressible°ow in comparison with the classical frequency domain or discrete domain method.This new method is applied to identify the unsteady°uid dynamic models of a NACA0012 airfoil and the e®ect of the°uid viscosity on the model parameter is analyzed.The result shows that the added mass in viscous°ow is dependent on the input signal frequency and is exactly the added mass in inviscid°ow when the frequency approaches innity.Based on this discovery,the long controversy on the relationship of added mass between viscous and inviscid°ow is solved.Then,the enlightenment of this discovery on the identication of both linear and nonlinear unsteady aerodynamic model in incompressible°ow is illustrated.At last,the advantage of the new acquired unsteady°uid dynamic model is discussed in comparison with the classical quasi-steady aerodynamic model.展开更多
The concept of object identity and implementation of object identity in some sys-tems have been explained in literature. Based on an analysis on the idea of data schemein ANSI/X3/SPARC, this paper presents the concept...The concept of object identity and implementation of object identity in some sys-tems have been explained in literature. Based on an analysis on the idea of data schemein ANSI/X3/SPARC, this paper presents the concept of fulLidentity which includesentity identity conceptual object identity and internal object identity In addition, theequality of objects, which is richer and more practical, is discussed based on the fullidentity of objects. Therefore, the semanics and constructions of the identity for thecomplex objects are fully observed, and some appllactions in object management, version management, and user interface are found. Also, it could support the combinationof O-O model with Vo model.展开更多
文摘To identify the unsteady°uid dynamic model for a solid moving in the°uid,a new identication method that operates in the continuous time domain is proposed.It is illustrated that this new identication method is more accurate and appropriate for identifying unsteady°uid dynamic model in incompressible°ow in comparison with the classical frequency domain or discrete domain method.This new method is applied to identify the unsteady°uid dynamic models of a NACA0012 airfoil and the e®ect of the°uid viscosity on the model parameter is analyzed.The result shows that the added mass in viscous°ow is dependent on the input signal frequency and is exactly the added mass in inviscid°ow when the frequency approaches innity.Based on this discovery,the long controversy on the relationship of added mass between viscous and inviscid°ow is solved.Then,the enlightenment of this discovery on the identication of both linear and nonlinear unsteady aerodynamic model in incompressible°ow is illustrated.At last,the advantage of the new acquired unsteady°uid dynamic model is discussed in comparison with the classical quasi-steady aerodynamic model.
文摘The concept of object identity and implementation of object identity in some sys-tems have been explained in literature. Based on an analysis on the idea of data schemein ANSI/X3/SPARC, this paper presents the concept of fulLidentity which includesentity identity conceptual object identity and internal object identity In addition, theequality of objects, which is richer and more practical, is discussed based on the fullidentity of objects. Therefore, the semanics and constructions of the identity for thecomplex objects are fully observed, and some appllactions in object management, version management, and user interface are found. Also, it could support the combinationof O-O model with Vo model.
