System identification of a vortex lattice aerodynamic model

AIAA Journal ◽  
2002 ◽  
Vol 40 ◽  
pp. 1187-1196
Author(s):  
J.-N. Juang ◽  
D. Kholodar ◽  
E. H. Dowell
Keyword(s):  
System Identification ◽  
Vortex Lattice ◽  
Aerodynamic Model

scholarly journals System Identification of a Vortex Lattice Aerodynamic Model

AIAA Journal ◽  
2002 ◽  
Vol 40 (6) ◽  
pp. 1187-1196 ◽  
Author(s):  
Jer-Nan Juang ◽  
Denis Kholodar ◽  
Earl H. Dowell
Keyword(s):  
System Identification ◽  
Vortex Lattice ◽  
Aerodynamic Model

A Time-Domain Fluid-Structure Interaction Analysis of Fan Blades

2008 ◽  
Author(s):  
Seung Ho Cho ◽  
Taehyoun Kim ◽  
Seung Jin Song
Keyword(s):  
Time Domain ◽  
Vortex Lattice ◽  
Interaction Analysis ◽  
Three Dimensional ◽  
Incoming Flow ◽  
Structure Interaction ◽  
Unsteady Aerodynamic ◽  
Aerodynamic Model ◽  
Blade Row ◽  
Fan Blade

This paper presents aerodynamic and aeromechanical analyses for an entire row of fan blades (i.e. tens of blades with a finite aspect ratio) subject to a uniform incoming flow. In this regard, a new unsteady three-dimensional vortex lattice model has been developed for multiple blades in discrete time domain. Using the new model, the characteristics of the unsteady aerodynamic forces on vibrating blades, including their temporal development, are examined. Also, the new aerodynamic model is applied to examine the aeromechanical behavior of fan blades by using a standard eigenvalue analysis. For this analysis, the fan blades have been modeled as three-dimensional plates, and, increasing the number of blades (or solidity) is predicted to destabilize the fan blade row.

Part 2 — Longitudinal aircraft motions with attached flow

1987 ◽  
Vol 91 (901) ◽  
pp. 4-20 ◽  
Keyword(s):  
Vortex Lattice ◽  
Aerodynamic Model ◽  
Flow Past ◽  
Lattice Representation ◽  
Attached Flow ◽  
Aircraft Configurations

Summary An axiomatic aerodynamic model is formulated for the attached flow past a wing and tailplane, based on a vortex lattice representation, with the wing wake fully relaxed at each instant of time. Conventional derivatives are estimated based on this model. Predicted responses, using the above derivatives, are compared with ‘exact’ responses, using the axiomatic model for various elevator inputs and for both non-swept and swept aircraft configurations. Surprisingly, even in these simpler cases, differences appear between prediction and ‘exact’ responses.

Aerodynamic model of propeller–wing interaction for distributed propeller aircraft concept

2019 ◽  
Vol 234 (10) ◽  
pp. 1688-1705 ◽  
Author(s):  
Baizura Bohari ◽  
Quentin Borlon ◽  
Murat Bronz ◽  
Emmanuel Benard
Keyword(s):  
Experimental Data ◽  
Vortex Lattice ◽  
Numerical Models ◽  
Aircraft Design ◽  
Computational Time ◽  
Nonlinear Prediction ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Blade Element Theory ◽  
Aerodynamic Model

The present investigation addresses two key issues in aerodynamic performance of a propeller–wing configuration, namely linear and nonlinear predictions with low-order numerical models. The developed aerodynamic model is targeted to be used in the preliminary aircraft design loop. First, the combination of selected propeller model, i.e. blade element theory with the wing model, i.e. lifting line theory and vortex lattice method is considered for linear aerodynamic model. Second, for the nonlinear prediction, a modified vortex lattice method is paired with the two-dimensional viscous effect of the airfoils to simplify and reduce the computational time. These models are implemented and validated with existing experimental data to predict the differences in lift and drag distribution. Overall, the predicted results show agreement with low percentage of error compared with the experimental data for various thrust coefficients and produced induced drag distribution that behaves as expected.

A Community Based High Risk Register for Hearing Loss

1982 ◽  
Vol 47 (4) ◽  
pp. 373-375 ◽  
Author(s):  
James L. Fitch ◽  
Thomas F. Williams ◽  
Josephine E. Etienne
Keyword(s):  
Hearing Loss ◽  
System Identification ◽  
High Risk ◽  
Language Learning ◽  
Education Program ◽  
Communication System ◽  
Auditory Signal ◽  
Early Age ◽  
Community Based ◽  
Children With Hearing Loss

The critical need to identify children with hearing loss and provide treatment at the earliest possible age has become increasingly apparent in recent years (Northern & Downs, 1978). Reduction of the auditory signal during the critical language-learning period can severely limit the child's potential for developing a complete, effective communication system. Identification and treatment of children having handicapping conditions at an early age has gained impetus through the Handicapped Children's Early Education Program (HCEEP) projects funded by the Bureau of Education for the Handicapped (BEH).

Sign in / Sign up

Export Citation Format

Share Document