Two-Dimensional Model for Simulating Shock-Wave Interaction with Rigid Porous Materials

The evolution of upstream propagating shock waves from the isolated transonic compressor designated NASA Rotor-35 is examined numerically. Results from the numerical simulations are compared with those from a semi-analytical two-dimensional model based on the nonlinear acoustic interaction of shock waves in the axial–tangential plane upstream of the rotor. The evolution determined from a two-dimensional viscous computational solution is found to agree well with the semi-analytical prediction and confirms that shock wave evolution is a primarily inviscid phenomenon. Radial variations are found to increase the rate of decay of the shock wave amplitude in comparison to the prediction from the semi-analytical two-dimensional model. The velocity field from the three-dimensional viscous solution compares well with experimental measurements, indicating that the initial shock strength and shock wave evolution immediately upstream of the rotor blade leading edge are accurately captured. The upstream-propagating shock system is found responsible for nearly 20% of the total loss attributable to the rotor, and is consistent with earlier transonic airfoil cascade studies. The axial decay rate of the upstream induced circumferential static pressure distortion is found to be an order of magnitude slower at spanwise locations with supersonic relative inlet Mach numbers than those at which it is subsonic. As a consequence of this slower decay rate, it is found that the axial gap to the upstream stator would need to be about twice that used for subsonic blade sections.

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Evolution of Upstream Propagating Shock Waves From a Transonic Compressor Rotor

Journal of Turbomachinery ◽

10.1115/1.1516813 ◽

2003 ◽

Vol 125 (1) ◽

pp. 133-140 ◽

Cited By ~ 10

Author(s):

Anil Prasad

Keyword(s):

Shock Wave ◽

Shock Waves ◽

Decay Rate ◽

Analytical Prediction ◽

Two Dimensional ◽

Dimensional Model ◽

Tangential Plane ◽

Wave Evolution ◽

Transonic Compressor ◽

Two Dimensional Model

The evolution of upstream propagating shock waves from the isolated transonic compressor designated NASA Rotor-35 is examined numerically. Results from the numerical simulations are compared with those from a semi-analytical two-dimensional model based on the nonlinear acoustic interaction of shock waves in the axial-tangential plane upstream of the rotor. The evolution determined from a two-dimensional viscous computational solution is found to agree well with the semi-analytical prediction and confirms that shock wave evolution is a primarily inviscid phenomenon. Radial variations are found to increase the rate of decay of the shock wave amplitude in comparison to the prediction from the semi-analytical two-dimensional model. The velocity field from the three-dimensional viscous solution compares well with experimental measurements, indicating that the initial shock strength and shock wave evolution immediately upstream of the rotor blade leading edge are accurately captured. The upstream-propagating shock system is found responsible for nearly 20% of the total loss attributable to the rotor, and is consistent with earlier transonic airfoil cascade studies. The axial decay rate of the upstream induced circumferential static pressure distortion is found to be an order of magnitude slower at spanwise locations with supersonic relative inlet Mach numbers than those at which it is subsonic. As a consequence of this slower decay rate, it is found that the axial gap to the upstream stator would need to be about twice that used for subsonic blade sections.

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NUMERICAL ANALYSIS OF TWO-DIMENSIONAL PROBLEM OF SUPERSONIC SHOCK WAVE INTERACTION WITH A BOUNDARY LAYER

Information systems mechanics and control ◽

10.20535/2219-380412201551164 ◽

2015 ◽

Vol 0 (12) ◽

pp. 48

Author(s):

Анатолій Юрійович Педченко ◽

Євген Миколайович Панов ◽

Антон Янович Карвацький ◽

Сергій Володимирович Лелека ◽

Тарас Валерійович Лазарєв

Keyword(s):

Boundary Layer ◽

Shock Wave ◽

Numerical Analysis ◽

Wave Interaction ◽

Two Dimensional ◽

Dimensional Problem ◽

Shock Wave Interaction ◽

Supersonic Shock

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Commitment to pro- versus counter-attitudinal behavior and the dynamics of social representations

Swiss Journal of Psychology ◽

10.1024//1421-0185.61.1.34 ◽

2002 ◽

Vol 61 (1) ◽

pp. 34-44 ◽

Cited By ~ 8

Author(s):

Eric Tafani ◽

Lionel Souchet

Keyword(s):

Higher Education ◽

Social Representations ◽

Cognitive Restructuring ◽

Social Representation ◽

Two Dimensional ◽

Dimensional Model ◽

Social Actions ◽

The Social ◽

Two Dimensional Model ◽

Students Attitudes

This research uses the counter-attitudinal essay paradigm ( Janis & King, 1954 ) to test the effects of social actions on social representations. Thus, students wrote either a pro- or a counter-attitudinal essay on Higher Education. Three forms of counter-attitudinal essays were manipulated countering respectively a) students’ attitudes towards higher education; b) peripheral beliefs or c) central beliefs associated with this representation object. After writing the essay, students expressed their attitudes towards higher education and evaluated different beliefs associated with it. The structural status of these beliefs was also assessed by a “calling into question” test ( Flament, 1994a ). Results show that behavior challenging either an attitude or peripheral beliefs induces a rationalization process, giving rise to minor modifications of the representational field. These modifications are only on the social evaluative dimension of the social representation. On the other hand, when the behavior challenges central beliefs, the same rationalization process induces a cognitive restructuring of the representational field, i.e., a structural change in the representation. These results and their implications for the experimental study of representational dynamics are discussed with regard to the two-dimensional model of social representations ( Moliner, 1994 ) and rationalization theory ( Beauvois & Joule, 1996 ).

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