Dynamics Of An Incompressible, Inviscid Flow Field

2021 ◽  
pp. 88-165
Keyword(s):  
1983 ◽  
Vol 105 (3) ◽  
pp. 530-535 ◽  
Author(s):  
S. Abdallah ◽  
A. Hamed

This paper presents the elliptic solution of the inviscid incompressible secondary flow in curved passages. The three-dimensional flow field is synthesized between 3 sets of orthogonal nonstream surfaces. The two-dimensional flow field on each set of surfaces is considered to be resulting from a source/sink distribution. The distribution and strength of these sources are dependent on the variation in the flow properties normal to the surfaces. The dependent variables in this formulation are the velocity components, the total pressure, and the main flow vorticity component. The governing equations in terms of these dependent variables are solved on each family of surfaces using the streamlike function formulation. A new mechanism is implemented to exchange information between the solutions on the three family surfaces, resulting into a unique solution. In addition, the boundary conditions for the resulting systems of equations are carefully chosen to insure the existence and uniqueness of the solution. The numerical results obtained for the rotational inviscid flow in a curved duct are discussed and compared with the available experimental data.


1979 ◽  
Vol 83 (1) ◽  
pp. 59-77 ◽  
Author(s):  
STUART B. SAVAGE ◽  
BARRY G. NEWMAN ◽  
DENIS T.-M. WONG

Weis-Fogh and Norberg concluded that steady-state aerodynamics is incapable of explaining how the dragonfly supports its weight during hovering. Norberg also concluded that the wing kinematics of Aeschna juncea L., as determined photographically, are incompatible with those proposed by Weis-Fogh for his Flip mechanism. The present paper has proposed an alternative lift-generating mechanism, various aspects of which are novel from the standpoint of animal flight. Flow visualization tests performed in water established the flow field during a complete cycle of the idealized wing motion. Using this information and unsteady inviscid flow theory the forces were analysed. A plausible balance of horizontal forces and more than sufficient lift were obtained. A physical explanation of the theory is provided for those who do not wish to study the mathematical details.


1980 ◽  
Vol 102 (3) ◽  
pp. 297-301 ◽  
Author(s):  
A. Hamed ◽  
E. Baskharone

The present analysis describes the three dimensional compressible inviscid flow in the scroll and the vaneless nozzle of a radial inflow turbine. The solution to this flow field, which is further complicated by the geometrical shape of the boundaries, is obtained using the finite element method. Symmetric and nonsymmetric scroll cross sectional geometries are investigated to determine their effect on the general flow field and on the exit flow condiitons.


Author(s):  
A. Yalpaniyan ◽  
M. Goodarzi

A TLP is a buoyant platform containing four cylindrical columns. The purpose of this study was to consider the effects of different model solvers in the numerical solution on the flow pattern around the TLP. The flow around the TLP was numerically simulated with inviscid, laminar, and turbulent solvers. Three Froude numbers were run for each case. There was a symmetry plane that allowed simulating just one half of the flow field. Therefore, two columns along the symmetry plane were considered in the results discussion. Beside the generated surface waves there was a pair of vortex behind each column none of them were actually symmetric. The vortex behind the first column significantly affected the flow pattern around the second one in the manner that the vortex behind the first column was larger than the next one. In all cases the outer vortex was larger than the inner one. The obtained results showed that the generated waves of the inviscid flow were smoother than the turbulent flow, and also those of the turbulent flow were smoother than the laminar ones. Compared to the mentioned results, the influence of the flow velocity on the wave heights was more significant.


Author(s):  
A. W. Reichert ◽  
H. Simon

The design of radial inflow turbine guide vanes depends very much on the discharge conditions desired, especially if the choking mass flow is reached. Because of the choking mass flow condition and supersonic discharge Mach numbers, an inverse design procedure based on the method of characteristics is presented. Various designs which correspond to different discharge Mach numbers are shown. Viscous and inviscid flow field calculations for varying discharge conditions show the properties of the guide vanes at design and off–design conditions. In a previous paper (Reichert and Simon 1994), an optimized design for transonic discharge conditions has been published. In the present paper, additional results concerning the optimum design are presented. For this optimum design an advantageous adjusting mechanism for a variable geometry guide vane has been developed. The effect of guide vane adjustment on the discharge conditions has been investigated using viscous flow field calculations.


1986 ◽  
Vol 108 (2) ◽  
pp. 187-193 ◽  
Author(s):  
M. L. Celestina ◽  
R. A. Mulac ◽  
J. J. Adamczyk

This paper presents the results of a numerical simulation of the time-averaged inviscid flow field through the blade rows of a multiblade row turboprop configuration. The governing equations are outlined along with a discussion of the solution procedure and coding strategy. Numerical results obtained from a simulation of the flow field through a modern high-speed turboprop will be shown.


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