Abstract
This paper presents an approximate method for determining separation points in laminar flows. The method of solution of the boundary layer equations uses two integrated equations: the main characteristic of the method is that its approximations (based on a representation of the velocity profiles by means of the Taylor formula) are only in integrals. The first-order approximation gives the solution in closed form and is accurate for accelerated flows and for decelerated flows when the non-dimensional axial derivative of the pressurep x is less than 0.5: for stronger adverse pressure gradients accurate results are obtained by means of the third approximation.
The same method was applied successfully to the energy equation.
Sommario
Questo lavoro presenta un metodo approssimato per determinare i punti di separazione in flussi laminari. Il metodo di soluzione delle equazioni dello strato limite utilizza le derivate dell'equazione della quantita' di moto e due equazioni integrate: la caratteristica fondamentale del metodo risiede nell'approssimare (mediante una rappresentazione dei profili di velocita' basata sulla formula di Taylor) solo integrali. La prima approssimazione da' la soluzione in forma chiusa ed e' accurata per flussi accelerati e per flussi decelerati quando la derivata della pressione assiale in forma adimensionalep x e' minore di 0.5: per gradienti di pressione piu' sfavorevoli risultati accurati si hanno con la terza approssimazione. Lo stesso metodo e' stato applicato con successo all'equazione dell'energia.
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References
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Pozzi, A., Teodori, A.R. Separation points in laminar flows. Meccanica 28, 53–59 (1993). https://doi.org/10.1007/BF00990289
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DOI: https://doi.org/10.1007/BF00990289