Author: Stephane BaralonPublisher:
ISBN: 9789171979179
Category :
Languages : en
Pages : 137
Book Description
On Multistage Analysis of Transonic Compressors
Author: Stephane BaralonPublisher:
ISBN: 9789171979179
Category :
Languages : en
Pages : 137
Book Description
Transonic Compressor Analysis. Volume I. Methodology
Author: John I. ErdosPublisher:
ISBN:
Category :
Languages : en
Pages : 61
Book Description
A method of analysis of transonic multistage compressors is described. The three dimensional, compressible non-steady flow equations are solved numerically by a finite difference method subject to steady boundary conditions. The approach utilizes circumferential averaging of flow properties; however the essential aspects of three dimensional flow are retained through consideration of a three component blade force and blockage of the annular area due to the combined effects of blade thickness and actual circumferential variations in the flow. (Author).
Analysis of a Highly Loaded, Transonic, Inlet Compressor Stage
Author: David CarAnalysis of Three-dimensional Transonic Compressors
Author: Antoine BourgeadePublisher:
ISBN:
Category : Aerodynamics, Transonic
Languages : en
Pages : 114
Book Description
Flow in Multistage Transonic Compressors
Author: Anthony DentModeling Multi-stage Flows and Aeroelasticity in Transonic Gas Turbine Compressors
Author: Roy Milton CulverPublisher:
ISBN: 9781109509311
Category :
Languages : en
Pages : 179
Book Description
Modern desire to have turbomachines perform over a large range of conditions raises concerns as to their susceptibility to potentially harmful vibrations induced by the unsteady flows encountered at conditions far from the design point. Machines demonstrating this type of behavior may be damaged by fatigue or be subject to catastrophic failure. Due to these concerns and the relative expense and difficulty in obtaining accurate experimental data for fluid-structure interaction in turbomachines, computations have been and will continue to be an indispensable part of the design and research efforts focused on avoiding such phenomena. While the traditional computational analysis considering a single isolated blade row can aid in understanding the mechanisms that initiate vibrations in turbomachines, study of multiple blade rows may be necessary to completely model the underlying causes of these vibrations. In the present work, the mixing-plane and sliding-mesh methods are used to simulate both steady and unsteady multi-stage transonic compressor flows. The simulations conducted here include the solution of the compressible unsteady Reynolds Averaged Navier Stokes (RANS) Equations. The Spalart Almaras model is used to simulate the effects of turbulence in the flow field. A modal superposition method is used to model fluid-structure interaction resulting from blade vibration. Steady flow through the NASA Stage 35 transonic compressor is computed using the mixing-plane method, and reasonable agreement is obtained with experimental data and previous computations. Steady and unsteady computations are also performed for a modern 1.5-stage transonic compressor design provided by Siemens. For this case, experiments indicate the appearance of low frequency, large amplitude flow oscillations which could potentially lead to unwanted structural vibration. In performing unsteady computations for the Siemens compressor, effects of the periodic domain size for the sliding-mesh computations are considered by doubling and tripling the initial domain size. Computations performed on the triple-sized domain show a qualitatively different character than those performed with the two smaller domains. While this result cannot guarantee that the large domain has fully resolved the unsteady flow, it provides a strong argument that the two smaller domains have not, and highlights the need to clearly identify the circumferential wavelengths expected in an unsteady multi-stage flow. Fluid-structure interaction computations for this case show very small amplitude vibrations.
Analysis of the Effects of Design Pressure Ratio Per Stage and Off-design Efficiency on the Operating Range of Multistage Axial-flow Compressors
Author: Melvyn SavagePublisher:
ISBN:
Category : Axial flow compressors
Languages : en
Pages : 40
Book Description
Multistage compressors composed of high-pressure-ratio stages have higher over-all off-design efficiencies and a wider operating range than those made up of low-pressure-ratio stages if the blade-row efficiency curves for the two cases are assumed to be somewhat similar.
Computational Analysis of a Multistage Axial Compressor
Author: Chaithanya MamidojuPublisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
Turbomachines are used extensively in Aerospace, Power Generation, and Oil & Gas Industries. Efficiency of these machines is often an important factor and has led to the continuous effort to improve the design to achieve better efficiency. The axial flow compressor is a major component in a gas turbine with the turbine's overall performance depending strongly on compressor performance. Traditional analysis of axial compressors involves through flow calculations, isolated blade passage analysis, Quasi-3D blade-to-blade analysis, single-stage (rotor-stator) analysis, and multi-stage analysis involving larger design cycles. In the current study, the detailed flow through a 15 stage axial compressor is analyzed using a 3-D Navier Stokes CFD solver in a parallel computing environment. Methodology is described for steady state (frozen rotor stator) analysis of one blade passage per component. Various effects such as mesh type and density, boundary conditions, tip clearance and numerical issues such as turbulence model choice, advection model choice, and parallel processing performance are analyzed. A high sensitivity of the predictions to the above was found. Physical explanation to the flow features observed in the computational study are given. The total pressure rise verses mass flow rate was computed.
An Experimental Two-stage Transonic Compressor
Author: R. K. OldhamTransonic Axial Compressor Design Case Study and Preparations for Testing
Author: William D. ReidPublisher:
ISBN:
Category :
Languages : en
Pages : 102
Book Description
Test runs of the transonic axial compressor test rig at the Naval Postgraduate School, Turbopropulsion Laboratory, were conducted in preparation for the installation of a new stage design. Modifications in the cooling air supply to the high speed bearings, and to the design of the torque measuring system were completed during subsequent overhaul. A case study of the design of the new transonic stage was initiated. This consisted of a review of the procedure used in the design, as well as a design comparison. The comparison examined the differences between the blades designed for the new stage, which was primarily accomplished using a full, three- dimensional, Computational Fluid Dynamics code, and blades designed using two-dimensional streamline curvature methods. The axi-symmetric through-flow code, used in the design case study was modified to run on workstations at the Naval Postgraduate School, Department of Aeronautics and Astronautics, providing students and faculty with a design tool for single or multiple stage axial flow compressors.