Axial Compressor Stator Aerodynamics

1985 ◽  
Vol 107 (2) ◽  
pp. 485-492 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Through Flow ◽  
Contour Plots ◽  
Two Dimensional Flow ◽  
Design Systems ◽  
The Difference ◽  
Design Analyses ◽  
Turbomachinery Design

Axisymmetric, through-flow calculations, currently the “backbone” of most multistage turbomachinery design systems, are being pushed to their limit. This is due to the difference between the complex, three-dimensional flows that actually occur in turbomachinery and the two-dimensional flow assumed in this type of analysis. To foster the development of design analyses that account more accurately for these three-dimensional effects, there is a need for detailed flow field data in a multistage environment. This paper presents a survey of the initial results from a detailed experimental study of the aerodynamics of the second stage of a large scale, two-stage axial compressor. Data were acquired over a range of flow coefficients. The data presented here are for the second stator and include airfoil and endwall flow visualization, and radial-circumferential traverse measurements presented in the form of fullspan contour plots of total pressure. Also presented are the spanwise distributions of total and static pressures, axial velocity, air angles, and blockage. The effect of increased loading on the growth of the hub corner stall and its impact on these parameters is discussed.

scholarly journals Effects of morphology in controlling propagation of density currents in a reservoir using uncalibrated three-dimensional hydrodynamic modeling

2020 ◽  
Author(s):  
Behnam Zamani ◽  
Manfred Koch ◽  
Ben R. Hodges
Keyword(s):  
Hydrodynamic Model ◽  
Large Scale ◽  
Three Dimensional ◽  
Density Current ◽  
Density Currents ◽  
Large Reservoir ◽  
Bottom Water Temperature ◽  
The Difference ◽  
Basin Morphology ◽  
Southwest Iran

In this study, effects of basin morphology are shown to affect density current hydrodynamics of a large reservoir using a three-dimensional (3D) hydrodynamic model that is validated (but not calibrated) with in situ observational data. The AEM3D hydrodynamic model was applied for 5-month simulations during winter and spring flooding for the Maroon reservoir in southwest Iran, where available observations indicated that large-scale density currents had previously occurred. The model results were validated with near-bottom water temperature measurements that were previously collected at five locations in the reservoir. The Maroon reservoir consists of upper and lower basins that are connected by a deep and narrow canyon. Analyses of simulations show that the canyon strongly affects density current propagation and the resulting differing limnological characteristics of the two basins. The evolution of the Wedderburn Number, Lake Number, and Schmidt stability number are shown to be different in the two basins, and the difference is attributable to the morphological separation by the canyon. Investigation of the background potential energy (BPE) changes along the length of the canyon indicated that a density front passes through the upper section of the canyon but is smoothed into simple filling of the lower basin. The separable dynamics of the basins has implications for the complexity of models needed for representing both water quality and sedimentation.

scholarly journals Determination of Some Body Measurements of Camels With Three Dimensional Modeling Method (3D)

2021 ◽  
Author(s):  
Alkan çağlı ◽  
M. Yılmaz
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Practical Method ◽  
Modeling Method ◽  
The Body ◽  
Body Measurements ◽  
3D Measurement ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
The Difference

Abstract In this study, the use of three-dimensional modeling method was tested in taking some body measurements in camels with a practical method and was compared with other measurement methods. As the animal material of the study, 12 single humped dromedary female camels and 14 double humped Camelus dromedarius X Camelus bactrianus: F1 male camels, totally 26 camels, were used in three camel farms in Incirliova district of Aydın province. The body measurements taken from each animal by using different three methods, namely by Manuel Method (MM), by Photography Method (PM), and by Three Dimensional Modeling Method (3D) were the Cidago Height (CH), the Back Height (BH), the Rump Height (RH), the Body Length (BL), the Brisket Height (BRH), the Abdominal Height (AH), the Shoulder Width (SW) and the Rump Width (RW) and these values were compared with each other. As a result of this study, the mean values of MM and 3D measurement values were very close to each other and the difference between them was found to be statistically insignificant. (P<0.05). The difference between the means of PM and MM/3D measurement values was found to be significant. (P <0.05). In the measurements taken by MM, 3D, PM methods in male camels, the values obtained by MM and 3D methods for CH, BH, RH, BRH, AH, BL, and SW were very close to each other and the differences between them were found insignificant statistically (p < 0.05). On the determined regression graph, a linear was found between MM and 3D measurement values. As a result of this study, it has been determined that the 3D modeling method can be used as a remote and more practical method in determining the morphological features of large-scale animals such as camels more reliably, more easily and more practically.

Calculation of Fluid Motion in Axial Flow Turbomachines

1968 ◽  
Author(s):  
D. J. L. Smith ◽  
J. F. Barnes
Keyword(s):  
Experimental Work ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Streamline Curvature ◽  
Through Flow ◽  
Loss Distributions ◽  
The Matrix ◽  
Made In

In the last few years considerable progress has been made in calculating the three-dimensional flows through turbomachines. The two methods which appear to be widely used are what have come to be known as the “Streamline Curvature” and the “Matrix Through Flow” methods. At the National Gas Turbine Establishment, these advanced methods have been applied to existing turbomachines and this paper presents some of the calculated and experimental results for four axial flow machines. By making use of fairly simple loss distributions it has been found that these methods can assist towards the understanding of observed phenomena and, in the case of the axial compressor, they offer some prospect of being able to calculate the onset of surge. Also included is a brief report of work in progress to generate a computer program for the solution of the compressible velocity distribution around the surfaces of turbomachine blades, together with an indication of possible future experimental work.

scholarly journals Turbulent 2.5-dimensional dynamos

2016 ◽  
Vol 799 ◽  
pp. 246-264 ◽  
Author(s):  
K. Seshasayanan ◽  
A. Alexakis
Keyword(s):  
Turbulent Flows ◽  
Large Scale ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Wide Range ◽  
Two Dimensional Flow

We study the linear stage of the dynamo instability of a turbulent two-dimensional flow with three components $(u(x,y,t),v(x,y,t),w(x,y,t))$ that is sometimes referred to as a 2.5-dimensional (2.5-D) flow. The flow evolves based on the two-dimensional Navier–Stokes equations in the presence of a large-scale drag force that leads to the steady state of a turbulent inverse cascade. These flows provide an approximation to very fast rotating flows often observed in nature. The low dimensionality of the system allows for the realization of a large number of numerical simulations and thus the investigation of a wide range of fluid Reynolds numbers $Re$, magnetic Reynolds numbers $Rm$ and forcing length scales. This allows for the examination of dynamo properties at different limits that cannot be achieved with three-dimensional simulations. We examine dynamos for both large and small magnetic Prandtl-number turbulent flows $Pm=Rm/Re$, close to and away from the dynamo onset, as well as dynamos in the presence of scale separation. In particular, we determine the properties of the dynamo onset as a function of $Re$ and the asymptotic behaviour in the large $Rm$ limit. We are thus able to give a complete description of the dynamo properties of these turbulent 2.5-D flows.

Modelling of spanwise mixing in compressor through-flow computations

1997 ◽  
Vol 211 (3) ◽  
pp. 243-251 ◽  
Author(s):  
J Dunham
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Streamline Curvature ◽  
Wall Boundary Layer ◽  
Through Flow ◽  
Compressor Design ◽  
Multistage Compressors ◽  
End Wall

Although three-dimensional Navier-Stokes computations are coming into use more and more, streamline curvature through-flow computations are still needed, especially for multistage compressors, and where codes which run in minutes rather than hours are preferred. These methods have been made more realistic by taking account of end-wall effects and spanwise mixing by four aerodynamic mechanisms: turbulent diffusion, turbulent convection by secondary flow, spanwise migration of aerofoil boundary layer fluid and spanwise convection of fluid in blade wakes. This paper describes the models adopted in the DRA streamline curvature method for axial compressor design and analysis. Previous papers are summarized briefly before describing the new part of the model—that accounting for aerofoil boundary layers and wakes. Other changes to the previously published annulus wall boundary layer model have been made to enable it to cater for separations and end bends. The resulting code is evaluated against a range of experimental and computational results.

Mathematical Model to Describe Double Circular Arc and Multiple Circular Arc Compressor Blading Profiles

2021 ◽  
Author(s):  
John Kidikian ◽  
Chelesty Badrieh ◽  
Marcelo Reggio
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Circular Arc ◽  
Engineering Software ◽  
Through Flow ◽  
Compressor Design ◽  
Design Software ◽  
Cartesian Coordinate ◽  
The One

Abstract For the past seven decades, a compressor aerodynamicist has developed various methodologies to design, analyze, and simulate compressor stages. In compressor design, three major subsequent steps can be identified: the one-dimensional mean-line methodology, the two-dimensional through-flow analysis, and the three dimensional computational fluid dynamics. One of the interconnecting threads, between these various x-dimensional analysis, is the compressor blade profile shape. This shape, of known and controllable geometric parameters, is usually accompanied by, or related to, loss models and known flow physics, either defined by theory or through experimental test. In this paper, a novel mathematical approach is described to define axial compressor airfoil profile shapes. These shapes, developed in a Cartesian coordinate system, can be used to create Double Circular Arc, Multiple Circular Arc, and a hybrid combination of the two types. The proposed methodology, based on the mathematics of circles, can be easily applied using generalized software such as Python or MATLAB, or be embedded in specialized engineering design software. In doing so, researchers and engineers can create compressor airfoil shapes which are consistent and flexible with respect to geometric parameter manipulation. Full details of the formulas, with respect to the camber line definition and the calculation of the profile intrados and extrados, are presented. A URL link to an equivalent MATLAB code, and a specialized engineering software, has been provided for those researchers that wish to apply the formulations and review its use.

A Three-Dimensional Unsteady Through-Flow Model for Rotating Stall in Axial Compressors

2020 ◽  
Author(s):  
Jin Guo ◽  
Jun Hu ◽  
Xuegao Wang ◽  
Rong Xu
Keyword(s):  
Flow Model ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Design Stage ◽  
Preliminary Evaluation ◽  
Source Terms ◽  
Axial Compressors ◽  
Through Flow

Abstract Rotating stall is a natural limit to the stable operating range of compressors due to the inverse pressure gradient of viscous gas. Effective prediction of compressor stall boundary is an important guarantee for the successful development of aeroengine. In this paper, a three-dimensional unsteady through-flow model based on body force theory is developed to reflect the dynamic stall process of multistage axial compressors with acceptable computational costs. The influence of blade geometric parameters is fully considered in blade force source terms. The source terms are related to the attack angle and Mach number of the blade inlet using the deviation angle and loss model in the through-flow theory. Meanwhile, the temporal lag response of the source terms to the upstream flow conditions is taken into account. Therefore, it can be utilized for predicting the off-design performance and rotating stall characteristics of multistage axial compressors. The developed model is validated on a two-stage low-speed axial compressor. The calculated performance line and stall cell speed are in agreement with the experimental results. The unsteady flow behavior of the compressor during stall is presented by the model. The results indicate that the developed model has the potential to be applied to the preliminary evaluation of compressor stability in design stage.

Flow Analysis of Axial Compressor AV63-15 Variable Stator Simulation

2012 ◽  
Vol 532-533 ◽  
pp. 474-478
Author(s):  
Wei Hua Cheng ◽  
Mian Chang Li ◽  
Chuan Peng Li
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Operating Conditions ◽  
Axial Flow Compressor ◽  
Air Supply ◽  
The Difference ◽  
And Performance ◽  
Flow Compressor

This paper conducts numerical simulation to a 15-stage civil axial flow compressor and obtains its main parameters distribution and performance curve by a full three-dimensional viscid flow computation software. The computation result indicates that, the developed axial flow compressor meets the anticipated design requirements, and satisfies the customers’ indicators. Under the designed compression ratio, the difference between the maximum air supply quantity in summer and the minimum air supply quantity in winter is 22%. By comparing the operating conditions and data analysis, obtained the change trend of axial velocity, static pressure and temperature, and Ma, and discovered that, under opening of 48° and outlet back pressure of 550KPa, flow separation occurred on the section of machine set close to hud, which indicated that operating condition was close to surging condition.

scholarly journals Vorticity forces on an impulsively started finite plate

2012 ◽  
Vol 694 ◽  
pp. 464-492 ◽  
Author(s):  
Jian-Jhih Lee ◽  
Cheng-Ta Hsieh ◽  
Chien C. Chang ◽  
Chin-Chou Chu
Keyword(s):  
Aspect Ratio ◽  
Three Dimensional ◽  
Longitudinal Component ◽  
Spanwise Direction ◽  
Two Dimensional ◽  
Force Analysis ◽  
Finite Plate ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
The Difference

AbstractIn this study, we consider various contributions to the forces on an impulsively started finite plate from the perspective of a diagnostic vorticity force theory. The wing plate has an aspect ratio (AR) between 1 and 3, and is placed at low and high angles of attack ($\ensuremath{\alpha} \leq $ and ${\gt }2{0}^{\ensuremath{\circ} } $), while the Reynolds number is either 100 or 300. The theory enables us to quantify the contributions to the forces exerted on the plate in terms of all of the fluid elements with non-zero vorticity, such as in the tip vortices (TiVs), leading- and trailing-edge vortices (LEV and TEV) as well on the plate surface. This line of force analysis has been pursued for two-dimensional flow in our previous studies. In contrast to the pressure force analysis (PFA), the vorticity force analysis (VFA) reveals new salient features in its applications to three-dimensional flow by examining sectional force contributions along the spanwise direction. In particular, at a large aspect ratio ($\mathit{AR}= 3$), the force distributions of PFA and VFA show close agreements with each other in the middle sections, while at a lower aspect ratio ($\mathit{AR}= 1$), the force distribution of PFA is substantially larger than that of VFA in most of the sections. The difference is compensated for by the contributions partly by the edge sections and mainly by the vortices in the outer regions. Further investigation is made fruitful by decomposing the vorticity into the spanwise (longitudinal) component (the only one in two-dimensional flow) and the other two orthogonal (transverse) components. The relative importance of the force contributions credited to the transverse components in the entire flow regions as well as in the two outer regions signifies the three-dimensional nature of the flow over a finite plate. The interplay between the LEV and the TiVs at various time stages is shown to play a key role in distinguishing the force contributions for the plate with a smaller aspect ratio and that with a larger aspect ratio. The present VFA provides a better perspective for flow control by relating the forces directly to the various sources of vorticity (or vortex structures) on or near the wing plate.

Sign in / Sign up

Export Citation Format

Share Document