Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: realizability

Sortuj według:

Ogranicz wyniki do:

A note on model matching for nonrealizable nonlinear systems

Halas M., Kotta U.

Archives of Control Sciences

2009

Vol. 19, no. 4

451-461

In this technical note the model matching problem for nonlinear systems not admitting the state space realization is discussed. Both continuous- and discrete-time cases are addressed. It is demonstrated, by using a transfer function formalism, that even in case of nonrealizable systems it is sometimes still possible to find realizable compensators.

A Nonlinear Turbulence Model for Simulating a Flow in a Square Duct

Naji H., Mompean G., Gnanga H., Rechia A.

Machine Dynamics Problems

2006

Vol. 30, No. 2

123-135

The aim of this paper is a priori evaluation and improvement of an explicit algebraic Reynolds stress model (EASM) which has been devised by Shih et al. (1995). This model which accounts for anisotropy is used to compute the turbulent flow through a square duct. It is based on a quadratic stress-strain relation which is obtained by applying the constraint of rapid distortion theory and the realizability constraint. The Reynolds number based on the averaged velocity and on the height of the duct is 4800. hi order to handle wall-proximity effects in the near-wall region, damping functions are implemented in the ShihM. Direct numerical simulation (DNS) of the Navier-Stokes equations is available for this case. The comparison of the ShihM results with these accurate simulations shows good agreements. The aspects of the state of such turbulent flow is summarized by the map of the second and third invariants of the Reynolds stress tensor.