Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 International Journal of Applied Mechanics and Engineering

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: unsteady boundary layer

Sortuj według:

Ogranicz wyniki do:

Strouhal number effects on dynamic boundary layer evolution over a wedge surface from initial flow to steady flow: analytical approach

Bachiri Mohamed, Bouabdallah Ahcen

International Journal of Applied Mechanics and Engineering

2022

Vol. 27, no. 4

26--39

The present work studies the effects of the physical parameter characterizing the laminar flow regime, namely the Strouhal number, on the evolution of the unsteady dynamic boundary-layer developed along a wedge surface. Similarity method is used to transform unsteady momentum equation to dimensionless form. Using superposition method between diffusion and convective flows solutions, an ad hoc velocity profile formula is proposed. The obtained results confirm perfectly the numerical data given by Blasius, Falkner-Skan and Williams-Rhyne for all Strouhal numbers. A new accurate analytical function of the local skin friction is established for all time values and for different wedge surface directions. In order to give further clarification on the flows evolutions from diffusion flow to convective flow, in the whole space domain, new skin friction coefficient curves are plotted for all Strouhal numbers and for different wedge surface directions.

Boundary layers growth on a moving surface due to an impulsive motion and a sudden increase of wall heat flux

Kumari M., Grosan T., Pop I.

International Journal of Applied Mechanics and Engineering

2008

Vol. 13, no 1

203-215

In this paper we investigate the development of the momentum and thermal boundary layers over a continuous moving semi-infinite flat plate when the extemal stream starts impulsively from rest at time t = O with a constant velocity [...] It is assumed that the plate starts to supply heat to the fluid at a constant rate qw at time t = O and maintained at this rate. The problem has been formulated in a new system of scaled coordinates such that for [...] it reduces to Rayleigh type of equation and for [...] (large time) it reduces to Blasius or Sakiadis type of equation. A new scale of dimensionless time ? has been used which reduces the region of time integration from an infinite region [...] to a finite time region [...] which reduces the computational time considerably. The goveming partial differential equations are transformed into a singular parabolic partial differential equations which have been solved numerically for a range of values of the goveming parameters using an implicit finite-difference scheme. The results show that there is a smooth transition from Rayleigh solution to Blasius or Sakiadis solution as the dimensionless time [...] increases from zero to one.