Aeroelastic Calculations Using CFD for a Typical Business Jet Model
Two time-accurate Computational Fluid Dynamics (CFD) codes were used to compute several flutter points for a typical business jet model. The model consisted of a rigid fuselage with a flexible semispan wing and was tested in the Transonic Dynamics Tunnel at NASA Langley Research Center where experimental flutter data were obtained from M(sub infinity) = 0.628 to M(sub infinity) = 0.888. The computational results were computed using CFD codes based on the inviscid TSD equation (CAP-TSD) and the Euler/Navier-Stokes equations (CFL3D-AE). Comparisons are made between analytical results and with experiment where appropriate. The results presented here show that the Navier-Stokes method is required near the transonic dip due to the strong viscous effects while the TSD and Euler methods used here provide good results at the lower Mach numbers.
Calculations of Unsteady Flow and Flutter by an Euler and Integral Boundary-Layer Method on Cartesian Grids
This paper presents an Euler and boundary-layer method capable of unsteady flow and aeroelastic simulations. An integral boundary-layer solver is coupled with an Euler solver in a “semi-inverse” manner. For the inviscid part, approximate wall boundaryconditions are implemented on non-moving mean chord positions, whereas the full nonlinear Euler equation is solved in the field for accurate resolution of shock waves and vorticity. Stationary Cartesian grids are used for both steady and unsteady calculations. An integral boundary-layer method using Green’s lag equation is coupled with the outer inviscid flow. Results of steady and unsteady calculations by this interactive boundary-layer method are presented and compared with experimental data. Flutter-boundary predictions for the 2D Isogai wing model are provided and compared with results using the Euler solver without the boundary-layer corrections and also thin-layer Navier-Stokes results. It shows that viscous effects are significant for this case.
Using Activity Theory in Developing Instructial Tools for Project Management Studies
Competence and skills of the project manager are significant to project success. The skills needed in project managersâ work cannot be learned only by reading the books or a lecture hall; one learns them by practice. Therefore, an important challenge for educational institutions is to develop pedagogical practices that allow students to participate in working life projects and to confront real-life problems. Project-based learning (PBL) offers a model that enables students to practice the skills and competences needed in working life projects by utilizing real-world work assignments in time-limited projects. Using PBL method alone does not necessarily guarantee learning result. In order to be successful, PBL method requires effective and competent supervision and guidance of students as well as appropriate tools for instruction. In this study the concepts from activity theory (AT) are applied to development tools for supervising project-based learning.