Three-dimensional inviscid flow analysis of turbofan forced mixers

1985 ◽  
Author(s):  
T. BARBER ◽  
G. MULLER ◽  
S. RAMSAY ◽  
E. MURMAN
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Inviscid Flow

Optimization of the Three-Dimensional Flow Path in the Scroll-Nozzle System of a Radial Inflow Turbine

1984 ◽  
Vol 106 (2) ◽  
pp. 511-515 ◽  
Author(s):  
E. A. Baskharone
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Three Dimensional Flow ◽  
Multiply Connected ◽  
Dimensional Flow ◽  
Nozzle Configuration ◽  
Flow Domain ◽  
Radial Inflow Turbine ◽  
Compressibility Effects

A three-dimensional inviscid flow analysis in the combined scroll-nozzle system of a radial inflow turbine is presented. The coupling of the two turbine components leads to a geometrically complicated, multiply-connected flow domain. Nevertheless, this coupling accounts for the mutual effects of both elements on the three-dimensional flow pattern throughout the entire system. Compressibility effects are treated for an accurate prediction of the nozzle performance. Different geometrical configurations of both the scroll passage and the nozzle region are investigated for optimum performance. The results corresponding to a sample scroll-nozzle configuration are verified by experimental measurements.

scholarly journals Numerical Simulation of Cascade Flow: Vortex Element Method for Inviscid Flow Analysis and Axial Turbine Blade Design

2021 ◽  
Vol 85 (2) ◽  
pp. 14-23
Author(s):  
Nono Suprayetno ◽  
Priyono Sutikno ◽  
Nathanael P. Tandian ◽  
Firman Hartono
Keyword(s):  
Best Practice ◽  
Lift Coefficient ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Turbine Rotor ◽  
Design Stage ◽  
Outer Diameter ◽  
Axial Turbine ◽  
Cascade Flow

This study aims to design an axial turbine rotor blade and predict the turbine performance at preliminary design stage. Quasi three dimensional method was applied to design including blade to blade flow analysis. The blade profile uses a NACA 0015 airfoil by varying the profile thickness from hub to tip. The profile is divided into eleven segments which has different parameters. The profile was analysed using blade to blade flow/cascade flow analysis called vortex panel method to obtain lift coefficient. The analysis of cascade flow was performed in potential flow and prediction of turbine perfomance is carried out involving common best practice to give drag effect on the blade. The design of the turbine was applied on three different rotors, which also have a different discharge, head, and design rotation. The outer diameter of turbine 1 is 0.65 m, while turbine 2 and turbine 3 have an outer diameter of 0,60 m. The calculation result show that the efficiency of turbines 1, 2, and 3 were 88,32%, 89,67%, and 89,04%, respectively.

scholarly journals A Rapid Aerodynamic Loading Procedure for Centrifugal Impeller Design

1994 ◽  
Author(s):  
J. H. G. Howard ◽  
Colin Osborne ◽  
David Japikse
Keyword(s):  
Industrial Design ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Design Procedure ◽  
Inviscid Flow ◽  
Centrifugal Impeller ◽  
Zone Model ◽  
Geometry Design ◽  
Loading Method ◽  
Rapid Loading

A crucial aspect of the design process for centrifugal impellers is the establishment of specific blade shapes. A rapid inviscid flow analysis procedure was developed for incorporation within a geometry manipulation code. Using a single streamtube model, a single-pass computation technique was generated. A two-zone model ensures that key features of the passage flow physics are incorporated. Several examples of industrial design problems are employed to demonstrate the capabilities of the rapid loading method and its use in a geometry design procedure (used by some 20 industrial design groups worldwide). Comparisons with a quasi-three-dimensional method are included. The rapid loading method is most accurate when the meridional stream paths have similar shapes to those for the hub and shroud contours. The technique is useful within a geometry generation program since rapid aerodynamic screening of candidate configurations is allowed with sufficient accuracy to avoid the need for quasi-three-dimensional approaches. If required, the final design may be analyzed using three-dimensional viscous flow calculation methods.

Measurement of Instantaneous Pressure and Velocity in Nonsteady Three-Dimensional Water Flow by Means of a Combined Five-Hole Probe

1980 ◽  
Vol 102 (2) ◽  
pp. 196-202 ◽  
Author(s):  
S. Matsunaga ◽  
H. Ishibashi ◽  
M. Nishi
Keyword(s):  
Water Flow ◽  
High Frequency ◽  
Flow Measurement ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Nonsteady Flow ◽  
High Frequency Response ◽  
Iterative Correction ◽  
Instantaneous Pressure

A new combined five-hole probe with hemispherical head of 2.0 mm diameter is developed for the measurement of nonsteady three-dimensional water flow. Each pressure hole is connected to a small semiconductor pressure transducer, which has a high frequency response, and the instantaneous pressure can be measured continuously by the probe. In the case of nonsteady flow, pressures detected by the probe are affected by the inertia due to flow unsteadiness. Therefore, in order to achieve an accurate nonsteady flow measurement, it is vital to reduce the inertial effects from the pressure reading. In the present study the inviscid flow analysis was carried out to evaluate the error due to the inertial effect, and the iterative correction procedure was examined by computer simulation.

A Three-Dimensional Viscous Transonic Inverse Design Method

2000 ◽  
Author(s):  
W. T. Tiow ◽  
M. Zangeneh
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Viscous Effects ◽  
Flow Equations ◽  
Flow Solution ◽  
Turbomachinery Blades ◽  
A Cell ◽  
Inverse Design Method ◽  
Euler Solver

The development and application of a three-dimensional inverse methodology is presented for the design of turbomachinery blades. The method is based on the mass-averaged swirl, rV~θ distribution and computes the necessary blade changes directly from the discrepancies between the target and initial distributions. The flow solution and blade modification converge simultaneously giving the final blade geometry and the corresponding steady state flow solution. The flow analysis is performed using a cell-vertex finite volume time-marching algorithm employing the multistage Runge-Kutta integrator in conjunction with accelerating techniques (local time stepping and grid sequencing). To account for viscous effects, dissipative forces are included in the Euler solver using the log-law and mixing length models. The design method can be used with any existing solver solving the same flow equations without any modifications to the blade surface wall boundary condition. Validation of the method has been carried out using a transonic annular turbine nozzle and NASA rotor 67. Finally, the method is demonstrated on the re-design of the blades.

Generation of steady longitudinal vortices in hypersonic boundary layer

2013 ◽  
Vol 729 ◽  
pp. 702-731 ◽  
Author(s):  
A. I. Ruban ◽  
M. A. Kravtsova
Keyword(s):  
Boundary Layer ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Viscosity Coefficient ◽  
Momentum Equation ◽  
The Body ◽  
Nonlinear Behaviour ◽  
Hypersonic Boundary Layer ◽  
Stagnation Temperature ◽  
Characteristic Distance

AbstractIn this paper we study the three-dimensional perturbations produced in a hypersonic boundary layer by a small wall roughness. The flow analysis is performed under the assumption that the Reynolds number, $R{e}_{0} = {\rho }_{\infty } {V}_{\infty } L/ {\mu }_{0} $, and Mach number, ${M}_{\infty } = {V}_{\infty } / {a}_{\infty } $, are large, but the hypersonic interaction parameter, $\chi = { M}_{\infty }^{2} R{ e}_{0}^{- 1/ 2} $, is small. Here ${V}_{\infty } $, ${\rho }_{\infty } $ and ${a}_{\infty } $ are the flow velocity, gas density and speed of sound in the free stream, ${\mu }_{0} $ is the dynamic viscosity coefficient at the ‘stagnation temperature’, and $L$ is the characteristic distance the boundary layer develops along the body surface before encountering a roughness. We choose the longitudinal and spanwise dimensions of the roughness to be $O({\chi }^{3/ 4} )$ quantities. In this case the flow field around the roughness may be described in the framework of the hypersonic viscous–inviscid interaction theory, also known as the triple-deck model. Our main interest in this paper is the nonlinear behaviour of the perturbations. We study these by means of numerical solution of the triple-deck equations, for which purpose a modification of the ‘skewed shear’ technique suggested by Smith (United Technologies Research Center Tech. Rep. 83-46, 1983) has been used. The technique requires global iterations to adjust the viscous and inviscid parts of the flow. Convergence of such iterations is known to be a major problem in viscous–inviscid calculations. In order to achieve improved stability of the method, both the momentum equation for the viscous part of the flow, and the equations describing the interaction with the flow outside the boundary layer, are treated implicitly in this study. The calculations confirm the fact that in this sort of flow the perturbations are capable of propagating upstream in the boundary layer, resulting in a perturbation field which surrounds the roughness on all sides. We found that the perturbations decay rather fast with the distance from the roughness everywhere except in the wake behind the roughness. We found that if the height of the roughness is small, then the perturbations also decay in the wake, though much more slowly than outside the wake. However, if the roughness height exceeds some critical value, then two symmetric counter-rotating vortices form in the wake. They appear to support themselves and grow as the distance from the roughness increases.

Obstacle drag in stratified flow

1990 ◽  
Vol 429 (1876) ◽  
pp. 119-140 ◽  
Keyword(s):  
Experimental Study ◽  
Linear Density ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Force Balance ◽  
Video Recordings ◽  
Lee Waves ◽  
Time Variations ◽  
Obstacle Height ◽  
Stable Linear

This paper describes an experimental study of the drag of two- and three-dimensional bluff obstacles of various cross-stream shapes when towed through a fluid having a stable, linear density gradient with Brunt-Vaisala frequency, N . Drag measurements were made directly using a force balance, and effects of obstacle blockage ( h / D , where h and D are the obstacle height and the fluid depth, respectively) and Reynolds number were effectively eliminated. It is shown that even in cases where the downstream lee waves and propagating columnar waves are of large amplitude, the variation of drag with the parameter K ( = ND /π U ) is qualitatively close to that implied by linear theories, with drag minima existing at integral values of K . Under certain conditions large, steady, periodic variations in drag occur. Simultaneous drag measurements and video recordings of the wakes show that this unsteadiness is linked directly with time-variations in the lee and columnar wave amplitudes. It is argued that there are, therefore, situations where the inviscid flow is always unsteady even for large times; the consequent implications for atmospheric motions are discussed.

Sign in / Sign up

Export Citation Format

Share Document