Viscous Analysis of Three-Dimensional Rotor Flow Using a Multigrid Method

1994 ◽  
Vol 116 (3) ◽  
pp. 435-445 ◽  
Author(s):  
A. Arnone
Keyword(s):  
Multigrid Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Maximum Flow ◽  
Variable Coefficients ◽  
Rotating Blade ◽  
A Cell ◽  
Space Discretization ◽  
Transonic Fan ◽  
Full Multigrid Method

A three-dimensional code for rotating blade-row flow analysis has been developed. The space discretization uses a cell-centered scheme with eigenvalue scaling for the artificial dissipation. The computational efficiency of a four-stage Runge–Kutta scheme is enhanced by using variable coefficients, implicit residual smoothing, and a full-multigrid method. An application is presented for the NASA rotor 67 transonic fan. Due to the blade stagger and twist, a zonal, nonperiodic H-type grid is used to minimize the mesh skewness. The calculation is validated by comparing it with experiments in the range from the maximum flow rate to a near-stall condition. A detailed study of the flow structure near peak efficiency and near stall is presented by means of pressure distribution and particle traces inside boundary layers.

Viscous Analysis of Three-Dimensional Rotor Flow Using a Multigrid Method

1993 ◽  
Author(s):  
A. Arnone
Keyword(s):  
Multigrid Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Maximum Flow ◽  
Variable Coefficients ◽  
Rotating Blade ◽  
A Cell ◽  
Space Discretization ◽  
Transonic Fan ◽  
Full Multigrid Method

A three-dimensional code for rotating blade-row flow analysis has been developed. The space discretization uses a cell-centered scheme with eigenvalues scaling for the artificial dissipation. The computational efficiency of a four-stage Runge-Kutta scheme is enhanced by using variable coefficients, implicit residual smoothing, and a full-multigrid method. An application is presented for the NASA rotor 67 transonic fan. Due to the blade stagger and twist, a zonal, non-periodic H-type grid is used to minimize the mesh skewness. The calculation is validated by comparing it with experiments in the range from the maximum flow rate to a near-stall condition. A detailed study of the flow structure near peak efficiency and near stall is presented by means of pressure distribution and particle traces inside boundary layers.

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.

scholarly journals BLOOD FLOW ANALYSIS OF POLYURETHANE HEART VALVES AT PEAK SYSTOLE

2006 ◽  
Vol 18 (01) ◽  
pp. 13-18
Author(s):  
CHEUNG-HWA HSU
Keyword(s):  
Blood Flow ◽  
Heart Valves ◽  
Stokes Equations ◽  
Flow Analysis ◽  
Anticoagulation Therapy ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Maximum Flow ◽  
Navier Stokes ◽  
Hemodynamic Characteristics

Polyurethane (PU) heart valves provide central flow at peak systole and the associated hemodynamic characteristics are superior to that of mechanical valves with almost no anticoagulation therapy for patients. Durability performances, on the other hand, are also superior to those of biological valves. This paper analyzes blood flow characteristics of the PU heart valves at fully open position with computational fluid dynamics. These data provide information for the improvement of leaflets and leaflet support geometry to minimize the scale of recirculation zone of the flow field. To simulate the hemodynamic characteristics of the blood flow, CFX-4.3 software with the finite volume method is utilized to analyze the three-dimensional Reynolds-averaged Navier-Stokes equations. By modifying the geometry of leaflets along with the supports, the scale of vortex flow and blood velocity are reduced obviously. Maximum flow velocity reduces 33% compared to that of original model at peak systole.

scholarly journals APPLICATION OF MULTIGRID METHOD TO THREE-DIMENSIONAL INCOMPRESSIBLE VISCOUS FLOW ANALYSIS AROUND SHELL ROOFS

2007 ◽  
Vol 72 (618) ◽  
pp. 135-142 ◽  
Author(s):  
Tomoshi MIYAMURA ◽  
Tomohiko KUMAGAI ◽  
Toshiyuki OGAWA ◽  
Shintaro OGATA ◽  
Makoto OHSAKI
Keyword(s):  
Viscous Flow ◽  
Multigrid Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Incompressible Viscous Flow

SAF file: It's really three dimensional file

2018 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Prof. Dr. Jamal Aziz Mehdi
Keyword(s):  
Cross Section ◽  
Root Canal ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Circular Motion ◽  
Root Canal Treatment ◽  
Metal Core ◽  
Rotating Blade

The biological objectives of root canal treatment have not changed over the recentdecades, but the methods to attain these goals have been greatly modified. Theintroduction of NiTi rotary files represents a major leap in the development ofendodontic instruments, with a wide variety of sophisticated instruments presentlyavailable (1, 2).Whatever their modification or improvement, all of these instruments have onething in common: they consist of a metal core with some type of rotating blade thatmachines the canal with a circular motion using flutes to carry the dentin chips anddebris coronally. Consequently, all rotary NiTi files will machine the root canal to acylindrical bore with a circular cross-section if the clinician applies them in a strictboring manner

Sign in / Sign up

Export Citation Format

Share Document