Methodology of air intake channel integration into aircraft layout using Unigraphics as the geometric modelling environment

Аuthors

Bibikov S. Y.^*, Katkova E. A.^**

*e-mail: batmail79@mail.ru
**e-mail: ekankat@gmail.com

Abstract

The article depicts methodology and gives recommendations on complex geometry air intake modelling process on the example of uncontrolled air intake. These recommendations have been elaborated considering many requirements and suggest the procedure, which could be used during air intake channels integration into aircraft layout.

Main requirements to the geometry (equivalent angle of subsonic diffuser) and relative length (Lch/Dent, Lch — channel length, Dent — diameter of engine entrance), as well as parameters of air intake entrance channel are imposed after all boundary conditions, such as air intake input square (F₀), air intake throat square (F_th) and optimal graphics of air intake duct squares are set. The suggested method for deceleration system integration allows the transfer to intake duct surface constructing with minimum iterations.

The practical part of this work includes recommendations to construct optimal complex duct surfaces using “Unigraphics” with allowance for their maximum optimization. We suggest to use “dynamic changes” method while designing air intake, i. e. changing associative construction with construction parameters changing (shape-generating parameters). Based on created geometry we plot the graph of air intake duct squares according to the squares obtained duct cross sections. It allows demonstrate the dissimilarity of actual duct geometric parameters from the presumed (optimal).

The above-described procedure allows select air intake and air duct location of supersonic jet with allowance for a large variety of layout limitations and gas dynamic requirements. It allows integrate air intake ducts of complex space form into aircraft layout under development with minimal time consumption. The suggested procedure of “dynamic” air intake duct geometry changing allows control changes of its geometric characteristics (graph of air intake duct squares function) and select thereby the duct parameters with subsequent optimization.

Keywords:

3D modeling, air inlet modeling, air channel of irregular shape, air inlet integration into aircraft layout, Gerlakh's diffuser, dynamic change of a form, air inlet braking system design

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