CAS2D- NONROTATING BLADE-TO-BLADE, STEADY, POTENTIAL TRANSONIC CASCADE
FLOW ANALYSIS CODE

( NASA Lewis Research Center )

     An exact, full-potential-equation model for the steady, irrotational,
homoentropic, and homoenergetic flow of a compressible, inviscid fluid
through a two-dimensional planar cascade together with its appropriate
boundary conditions has been derived. The CAS2D computer program numer-
ically solves an artificially time-dependent form of the actual full-
potential-equation, providing a nonrotating blade-to-blade, steady, po-
tential transonic cascade flow analysis code.

     Comparisons of results with test data and theoretical solutions indi-
cate very good agreement.

     In CAS2D, the governing equation is discretized by using type-
dependent, rotated finite differencing and the finite area technique. The
flow field is discretized by providing a boundary-fitted, nonuniform com-
putational mesh. This mesh is generated by using a sequence of conformal
mapping, nonorthogonal coordinate stretching, and local, isoparametric,
bilinear mapping functions. The discretized form of the full-potential
equation is solved iteratively by using successive line over relaxation.
Possible isentropic shocks are captured by the explicit addition of an ar-
tificial viscosity in a conservative form. In addition, a four-level, con-
secutive, mesh refinement feature makes CAS2D a reliable and fast algo-
rithm for the analysis of transonic, two-dimensional cascade flows. The
results from CAS2D are not directly applicable to three-dimensional, po-
tential, rotating flows through a cascade of blades because CAS2D does
not consider the effects of the Coriolis force that would be present in the
three-dimensional case.

     This program is written in FORTRAN IV for batch execution and has been
implemented on an IBM 370 series computer with a central memory require-
ment of approximately 200K of 8 bit bytes. The CAS2D program was developed
in 1980.

     COSMIC, and the COSMIC logo are registered trademarks of the National
Aeronautics and Space Administration. All other brands and product names
are the trademarks of their respective holders.



LANGUAGE: FORTRAN IV

MACHINE REQUIREMENTS: IBM 370 SERIES

PROGRAM SIZE: APPROXIMATELY 1,786 SOURCE STATEMENTS

DISTRIBUTION MEDIA: 9 Track 1600 BPI EBCDIC Card Image Format Magnetic Tape

PROGRAM NUMBER: LEW-13854

DOMESTIC - DOCUMENTATION PRICE: $16.00    PROGRAM PRICE: $500.00

INTERNATIONAL - DOCUMENTATION PRICE: $32.00   PROGRAM PRICE: $1000.00



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