In this paper we develop globally robustly stabilizing controllers for rotating stall and surge in multimode axial flow compressor models with uncertain pressure-flow compressor performance characteristic maps. Specifically, using Lyapunov stability theory, a novel switching nonlinear globally robustly stabilizing control law based on equilibria-dependent Lyapunov functions with converging doma...

Insoluble monolayers on water have been patterned at the macroscopic scale (i.e., at the centimeter scale of the flow apparatus) as well as the mesoscopic scale (i.e., down to the micron scale resolvable via optical microscopy). The macroscopic patterning at the air/water interface results from a hydrodynamic instability leading to a steadily precessing flow pattern. The velocity field is measu...

Carbon fibers are widely used in many industrial applications due the fact of their excellent properties. Carbonaceous mesophases are liquid crystalline precursor materials that can be spun into high performance carbon fibers using the melt spinning process, which is a flow cascade consisting of pressure driven flow-converging die flow-free surface extensional spinline flow that modifies the pr...

This paper presents the solution of the nonlinear equation that governs the flow of a viscous, incompressible fluid between two converging-diverging rigid walls using an improved homotopy analysis method. The results obtained by this new technique show that the improved homotopy analysis method converges much faster than both the homotopy analysis method and the optimal homotopy asymptotic meth...

Mathematically, the problem of flow field classification can be analyzed by eigenanalysis deformation-rate tensor; however, such analysis technique have not been commonly applied in fluid processing. We derive a simplified objective scheme based on invariants strain-rate tensor and vorticity tensor. Multiaxiality flow, which is related to type elongation, converging/bifurcating characterized te...

Abstract. A gradient based method is presented for optimization of an airfoil configuration. The flow is governed by two dimensional, compressible Euler equations. A finite volume code based on unstructured grid is developed to solve the equations. The procedure is carried out for optimizing an airfoil with initial configuration of NACA 0012. The advantage of this technique over the other gradi...

in this paper, economic convergence in selected oic (36 countries) is studied. the convergence hypothesis is tested through three approaches: beta convergence, sigma convergence, and time series model. ols is used for estimating the cross section model and cross variance is used to test the distributive model. for analyzing time series model, we used augmented dicky fuller test. beta convergenc...