Transonic flow analysis for rotors.



Publisher: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, Publisher: For sale by the National Technical Information Service] in [Washington, DC], [Springfield, Va

Written in English
Published: Downloads: 896
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Subjects:

  • Rotors (Helicopters),
  • Aerodynamics, Transonic.

Edition Notes

StatementI-Chung Chang.
SeriesNASA technical paper -- 2375.
ContributionsUnited States. National Aeronautics and Space Administration. Scientific and Technical Information Division.
The Physical Object
FormatMicroform
Pagination1 v.
ID Numbers
Open LibraryOL15368324M

Effect of tip winglets are investigated in compressor rotor cascade. Cascade investigation shows that rotor tip winglet are able to reduce total pressure loss due to tip leakage flow and blade passage secondary flow. Cascade studies are performed with winglet on blade suction side, pressure side and combination of both. The overall comparison between the predictions and the test data is reasonably good. A numerical study on a generic transonic compressor rotor was performed in which the impact of varying the amplitude of the airfoil oscillation on the normalized predicted magnitude and phase of the unsteady pressure around the airfoil was studied.   The test cases studied are NASA rotors 37 which have aspect ratios of and respectively. A 3D, single-passage steady flow Navier-Stokes solver was used to predict complete performance characteristics, including the numerical instability point, for both rotors. In this paper we describe a kind of unsteady phenomena in a transonic axial fan rotor at stable operating points based on the observation from numerical simulation results. Single-passage and full-annulus time-accurate simulations were implemented for several different operating points, when the unsteadiness phenomena occurred.

In order to be representative of these differing flow regimes the results of a range of tests at varying tip-gaps and speeds from subsonic to transonic are presented. A highly loaded transonic axial splittered rotor is used as the test article in this study. Three experiments with cold tip gaps of [mm], [mm] and [mm] are presented. CFD flow visualizations showed clearly a higher stall margin. The last stable operating point provided by the numerical model implemented gave a normalized mass flow of about 92% in the case of Rotor 37 (in accordance with experimental data) and about 90% in the case of redesigned version. The two rotors showed a similar choking mass flow rate. An understanding of the flow field induced by these phenomena seems essential to progress in reducing the losses in such rotors. This paper reports some results of a comprehensive investigation of the flow through such a high work transonic compressor rotor, being conducted at . Presented here are the numerical calculations of the 3D transonic flow of an ideal gas through an LP steam turbine last stage with exhaust hood, taking into account blade oscillations. The approach is based on a solution to the coupled aerodynamic-structure problem for 3D flow through a turbine stage using the partially integrated method.

An illustration of an open book. Books. An illustration of two cells of a film strip. Video An illustration of an audio speaker. Development of a Viscous Transonic Cascade Analysis. Item Preview remove-circle A research program has been conducted towards developing an analysis to predict viscous flow in a cascade blade passage. Two. Transonic flow patterns on an airfoil showing flow patterns at and above critical Mach number In aeronautics, transonic refers to the condition of flight in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an airfoil that are concurrently below, at, and above the speed of sound in the range of Mach 0. The design of an aft-swept transonic compressor rotor and the investigation of its flow field compared to the radial baseline rotor are reported. Both rotors were designed using a . works Search for books with subject Rotors (Helicopters). Search. Low-speed wind-tunnel test of an unpowered high-speed stoppable rotor Michael B. Lance Transonic flow analysis for rotors I-Chung Chang Read. An analysis of the gust-inducesd overspeed trends of helicopter rotors .

Transonic flow analysis for rotors. Download PDF EPUB FB2

Transonic flow analysis for rotors. [Washington, DC]: National Aeronautics and Space Administration, Scientific and Technical Information Branch ; [Springfield, Va.: For sale by the National Technical Information Service], (OCoLC) Material Type: Government publication, National government publication: Document Type: Book.

Get this from a library. Transonic flow analysis for rotors. Part 3, Three-dimensional, quasi-steady, Euler calculation. [I-Chung Chang; United States. National Aeronautics and Space Administration. Scientific and Technical Information Division.]. Abstract. The fact that helicopter rotors encounter transonic aerodynamic flow problems has been recognised for several years, and with this realisation there has been considerable activity in recent years in the study of ways of improving rotor performance through blade section and tip design [1–12].Cited by: 1.

Due to the transonic tandem rotor requiring a high stall margin, Appl. Sci. 10, 7 of 13 the rotor tip element needs to operate in a deep choke point, which makes the shock position move. The paper describes the flow conditions found inside an optimized transonic, high pressure ratio centrifugal compressor rotor operated with a rotor tip speed of m/s.

The rotor was coupled with a vaned diffuser of rather small exit radius ratio. Measurements and calculations were carried out on. COMPUTATIONAL ANALYSIS OF FLOW THROUGH A TRANSONIC COMPRESSOR ROTOR Nikolaus J.

Bochette Ensign, United States Navy B.S., United States Naval Academy, Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN MECHANICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL September Download Citation | Computational Analysis of Flow Through a Transonic Compressor Rotor | As the United States Navy prepares to field a single engine jet, the FC Joint Strike Fighter, it is.

Transonic rotor analyses use finite-difference Transonic flow analysis for rotors. book to solve the nonlinear flow equation. The rotor wake is a factor in almost all helicopter problems.

A major issue in advanced aerodynamic methods is how the wake can be included. Unsteady transonic aerodynamics is a field with many differences from its counterpart, steady aerodynamics.

The first volume of its kind, this text presents eight chapters and includes more than references and figures. Transonic ® offers several measurement solutions for the surgical suite including: Intraoperative volume flow through vessels and grafts during a wide range of surgeries including CABG, transplant and EC-IC bypass.

Non-invasive volume flow measurements through tubing used. This is a transonic flow case for which experimental results are available in the literature to compare [7].At inflow Mach number of and angle of attack of degrees, the adapted meshes and Mach number contours for levels 2 and 3 are shown in Figure 3, along with the initial mesh increased sharpness of the shock regions is evident from the results.

The effect of a single circumferential casing groove on the stability enhancement of two different transonic compressors has been examined with CFD analysis. The differences in flow field and stall inception mechanism between two rotors are presented with principal focus on passage blockage and tip leakage flow behavior.

Computational analysis has been conducted on the NASA Rotor 37 transonic compressor with various tip clearance gap heights.

Using steady rotor-only analysis, the change in overall performance, basic flow characteristics, and near-casing phenomena have been carefully observed. Single-Passage Analysis of Unsteady Flows Around Vibrating Blades of a Transonic Fan Under Inlet Distortion 9 April | Journal of Turbomachinery, Vol.No.

2 Transonic Rotor/Stator Interaction Using a 3-D Linearised Unsteady Viscous Flow Model. The interferogram in Fig. a shows a transonic interaction with shock-induced separation taking place in a channel, Fig. b giving an interpretative sketch of the flow field.

Boundary layer separation induces an oblique shock (C 1) after which the flow is still shock (C 1) meets the normal shock (C 3), cause of separation, at the point I, giving an interference. An in-depth analysis of three-dimensional flow structures reveals three features: (1) there exists an interface between the incoming main flow and the tip leakage flow, (2) in this rotor the tip leakage flows along the blade chord can be divided into at least two parts according to the blade loading distribution, and (3) each part plays a.

To focus on current ruggedization issues for transonic blading (e.g. bird, ice ingestion), detailed comparison of test data and analysis to characterize the aerodynamic flow details responsible for the measured performance differences was confined to the two rotors with the most forward location of maximum thickness.

Performance of Single-stage Axial-flow Transonic Compressor with Rotor and Stator Aspect Ratios of andRespectively, and with Design Pressure Ration of Volume of NASA technical paper: Author: Lonnie Reid: Publisher: National Aeronautics and Space Administration, Scientific and Technical Information Office, Original from.

The aerodynamics about rotors are very complex, encompassing subsonic to transonic flow with unsteady, stalled behavior and 3D effects. CA treats aerodynamics as separated into local and global flows.

Semi-empirical models of dynamic stall were created in the s–s for modeling unsteady local aerodynamics, including stalled flow. W.H. Mason, Configuration Aerodynamics 3/10/06 flow code known as FLO These were the first truly accurate and useful transonic airfoil analysis codes.

Holst has published a survey describing current full potential methods The next logical development was to add viscous effects to the inviscid calculations, and to.

Masaki, D, & Kaji, S. "Numerical Analysis of Transonic Compressor Rotor Flow Near Stall Points." Proceedings of the ASME International Gas Turbine and Aeroengine Congress and Exhibition.

Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery. Orlando, Florida, USA. June 2–5, VT03A ASME. The analytical design and experimental test of a single-stage transonic axial-flow compressor are described.

This design is the baseline of a compressor design study in which several blade design parameters have been systematically varied to determine their independent effects on. Effects of axial and tangential blade curvature were separately analyzed.

A commercial CFD package which solves the Reynolds-average Navier-Stokes equations was used to compute the complex flow field of transonic compressor rotors. The code was validated against NASA Rotor 37. The rig test confirmed the numerical assessment of the effects of aerodynamic sweep on the low-aspect-ratio, high-through-flow, transonic compressor rotor.

Detailed analyses of the measured and calculated flow fields indicate that two mechanisms are primarily responsible for the differences in aerodynamic performance among these rotors. Song, W.P., Han, Z.H., Qiao, Z.D.: Computational aeroacoustic prediction of transonic rotor noise based on Reynolds-Averaged Navier-Stokes flow simulation.

In: 25th Congress of the International Council of the Aeronautical Sciences, Paper ICASHamburg () Google Scholar. Moore, R., and Reid, L.,“Performance of Single-Stage Axial-Flow Transonic Compressor With Rotor and Stator Aspect Ratios of andRespectively.

Three-dimensional unsteady Navier—Stokes analysis of stator—rotor interaction in axial-flow turbines Show all authors.

L He 1. Flow analysis. Trans. Investigation of the unsteady flow of a transonic compressor using the nonlinear harmonic method. The performance deterioration of a high-speed axial compressor rotor due to surface roughness and airfoil thickness variations is reported.

A mm ( in.) thick rough coating with a surface finish of – rms μm (– rms μin.) is applied to the pressure and suction surface of the rotor blades. Transonic (or transsonic) flight is flying at or near the speed of sound ( m/s; 1, km/h; 1, ft/s; mph; kn, at sea level under average conditions), relative to the air through which the vehicle is traveling.

A typical convention used in aeronautics is to define transonic flight as speeds in the range of Mach to (–1, km/h (– mph) at sea level). The code has been used to study the complex flow fields of a transonic axial compressor rotor (i.e., NASA Rotor 37) and a subsonic centrifugal compressor impeller (i.e., the backswept impeller of Krain, first reported in ).

Transonic flow analysis for rotors. (Washington, D.C.: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division ; Springfield, Va.: For sale by the National Technical Information Service, ), by I-Chung Chang and United States.

National Aeronautics and Space Administration.A calculation system has been set up to predict both the internal flow field and the overall performance of a transonic compressor blade row.

The system iterates between an inviscid-viscous time-marching blade-to-blade (S1) treatment and a streamline curvature throughflow calculation for the pitchwise-averaged flow in the meridional plane (S2).This paper analyses the flow in a transonic turbine stage, using numerical results from a full 3D Navier-Stokes computation over the whole stage.

This analysis, based on the combination of time and space Fourier transforms, points out how a spatio-temporal periodicity phenomenon is involved in the so-called stator-rotor interaction.