A nonlinear computational aeroelasticity model for aircraft wings

The design of a large aircraft at high speeds is a challenge in the very active research on aeroelasticity. The computational aeroelasticity analysis in 3D for such a large system of nonlinear equations becomes available due to the recent highly developed computing technology. This thesis deals with the development of a CFD-based coupling code which is based on the equations of the structural motion and the Euler equations of inviscid compressible transonic flows. The strategy of segregating such a complex multidisciplinary system gives the advantages of the software development in modularity and the reuse of the developed solvers of the subsystems. The non-matching of the grids on the fluid-structure interface due to the difference of the element sizes and types of the fluid and the structural models is resolved by adding the matcher module in the coupling algorithm. The information transfers from one solver to another satisfy conservation of energy. The nonlinear aerodynamic model is described by the kinematic ALE description and discretized on the moving mesh which is updated by the mesh solver. The CSD-MAM model in which the modal superposition approach is based on the linear structural theories is used to reduce the computing time and the memory consumption. Another comparable CSD-FEM model based directly on the finite element discrete approach is also built for the extension to general structural dynamics. The nonlinearity is another source of the complexity of the aeroelasticity model although it is assumed only from the aerodynamics of the transonic flow and from the geometric nonlinearities due to the mesh motion. The nonlinear GMRES algorithm with the ILUT preconditioner is implemented in the robust CFD solver where the SUPG numerical stabilization techniques and a shock captor are applied to the transonic flow dominated by convection. The second order Gear-Scheme is used for the time discretization. The components of this nonlinear computational aeroelasticity model are validated one by one with numerical experiments. The complete model is validated by the AGARD 445.6 aeroelastic wing immersed in transonic flows with Mach number 0.96 which corresponds to the lowest point of the transonic dip. The flutter simulations have given satisfying results compared to experimental ones

Investigation of pressing process forlarge and thick blades of Francis turbines

Hot pressing process is very popular for thin plates in metal forming, such as in automotive construction. However, the process mechanism for very thick plates of high strength steel at hot temperature needs to be investigated. The process is characterized by thermo-mechanical behaviors, three-dimensional unsteady deformation and high nonlinearity. In this paper, the model of the process for manufacturing large and thick blades of Francis turbine is proposed. The process analysis is based on finite element method under ANSYS/LS-DYNA platform to get better understanding of the process. The whole process consists of the pressing forming of a blade from a flat blank, the springback after the forming and the cooling of the blade from hot temperature to room temperature. Investigation of the stress evolution is performed

Brucella Dysregulates Monocytes and Inhibits Macrophage Polarization through LC3-Dependent Autophagy

Brucellosis is caused by infection with Brucella species and exhibits diverse clinical manifestations in infected humans. Monocytes and macrophages are not only the first line of defense against Brucella infection but also a main reservoir for Brucella. In the present study, we examined the effects of Brucella infection on human peripheral monocytes and monocyte-derived polarized macrophages. We showed that Brucella infection led to an increase in the proportion of CD14++CD16− monocytes and the expression of the autophagy-related protein LC3B, and the effects of Brucella-induced monocytes are inhibited after 6 weeks of antibiotic treatment. Additionally, the production of IL-1β, IL-6, IL-10, and TNF-α from monocytes in patients with brucellosis was suppressed through the LC3-dependent autophagy pathway during Brucella infection. Moreover, Brucella infection inhibited macrophage polarization. Consistently, the addition of 3-MA, an inhibitor of LC3-related autophagy, partially restored macrophage polarization. Intriguingly, we also found that the upregulation of LC3B expression by rapamycin and heat-killed Brucella in vitro inhibits M2 macrophage polarization, which can be reversed partially by 3-MA. Taken together, these findings reveal that Brucella dysregulates monocyte and macrophage polarization through LC3-dependent autophagy. Thus, targeting this pathway may lead to the development of new therapeutics against Brucellosis

The effect of a therapeutic regimen of Traditional Chinese Medicine rehabilitation for post-stroke cognitive impairment: study protocol for a randomized controlled trial

Background Post-stroke cognitive impairment (PSCI) lessens quality of life, restricts the rehabilitation of stroke, and increases the social and economic burden stroke imposes on patients and their families. Therefore effective treatment is of paramount importance. However, the treatment of PSCI is very limited. The primary aim of this protocol is to propose a lower cost and more effective therapy, and to confirm the long-term effectiveness of a therapeutic regimen of Traditional Chinese Medicine (TCM) rehabilitation for PSCI. Methods/Design A prospective, multicenter, large sample, randomized controlled trial will be conducted. A total of 416 eligible patients will be recruited from seven inpatient and outpatient stroke rehabilitation units and randomly allocated into a therapeutic regimen of TCM rehabilitation group or cognitive training (CT) control group. The intervention period of both groups will last 12 weeks (30 minutes per day, five days per week). Primary and secondary outcomes will be measured at baseline, 12 weeks (at the end of the intervention), and 36 weeks (after the 24-week follow-up period). Discussion This protocol presents an objective design of a multicenter, large sample, randomized controlled trial that aims to put forward a lower cost and more effective therapy, and confirm the long-term effectiveness of a therapeutic regimen of TCM rehabilitation for PSCI through subjective and objective assessments, as well as highlight its economic advantages

SIMULATION OF A THREE-STAGE PROCESS FOR FORMING A CLOSED CONE FROM A PLATE

ABSTRACT High geometrical quality of bent cones is required in assembling several cone segments into a crown of Francis turbines. Although closed cones were successfully obtained using pyramidal three-roll conical bending machines with cylindrical rolls which is more adaptive and less expensive, the zones close to the leading and trailing edges of the plate never pass under the inner roll and remain planar. For the purpose of obtaining high geometrical quality, a three-stage process is proposed to obtain a jointed cone with no planar zones. The planar zones resulted from the first stage of the conical bending is eliminated after the repassing of the bent cone in the bending machine with the leading and trailing edges jointed together by forces. Numerical simulations with commercial software ANSYS/LS-DYNA in explicit scheme and ANSYS in implicit scheme are performed and bent cones with improved qualities are obtained

Modularity of service design for IT company

Applying modular logic to service design is crucial to service innovation; however, both under-modularity and over-modularity results in strategic mistakes, in particular to the IT service offering companies. This paper firstly identifies four dimensions of the conceptual modular IT service platform for designing and providing service to the customers. And a mathematical model is developed and applied to evaluate the degree of modularity for the designed unique services