Optimization of the Workflow of Multistage Axial Compressors Using Modern Gas Dynamics Computing Systems

2021 ◽  
Author(s):  
Grigorii Popov ◽  
Evgenii Goriachkin ◽  
Oleg Baturin ◽  
Valerii Matveev ◽  
Igor Egorov ◽  
...  

Published data on flat grid purges allow to evaluate the efficiency of blade devices with different kinematic scheme of stages and design parameters. The corresponding computer program ODOS-GP04 and examples of numerical analysis of the efficiency of flat grids and spatial blade devices of axial stages with different combinations of design parameters was provided. Further development of the ODOS-GP04 program is described below, which makes it possible to perform an estimated calculation of the gas-dynamic characteristics of the stages designed using this program. Analysis of the calculated characteristics of a number of typical stages allows to draw a conclusion about the influence of the main design parameters. This article is primarily addressed to people who are developing their knowledge of the gas dynamics of axial compressors. Some results of calculations do not correspond to the published experimental data. The authors expect that this may attract the attention of specialists working in the field of gas dynamics of axial compressors.


Author(s):  
Grigorii Popov ◽  
Evgenii Goriachkin ◽  
Oleg Baturin ◽  
Valerii Matveev ◽  
Igor Egorov ◽  
...  

Abstract Current developmental level of computers and numerical methods of gas dynamics makes it possible to optimize compressors using 3D CFD models. Design variants for the compressor can be automatically generated that best suit all the design requirements and limitations. However, the methods and tool for optimizing compressors are not sufficiently developed for the successful application. The problems lie in the large size of the calculation model, the solution time and the requirements for computer resources. In present study, a method for finding the optimal configuration of the blades of multi-stage axial compressors using 3D CFD modeling and commercial optimization programs as the main tools was developed. The basic parameters of the compressor (efficiency, pressure ratio, mass flow rate, etc.) can be improved using the created method correcting the shape of the blade profiles and their relative position. The method considers presence of various constraints. When developing the method, special attention was paid to the creation of an algorithm for parameterizing the blade shape and a program based on it, which can automatically change the shape of the axial compressor blades. They were used by the authors during optimization as a tool that converts variable parameters into the “new” blade geometry. Recommendations were also found on the rational settings for the CFD models used in the optimization of axial compressors. The paper provides a brief overview of several works related to the optimization of multi-stage gas turbine axial compressors for various purposes (number of stages from 3 to 15), successfully performed using the developed method. As a result, an increase was achieved in efficiency, pressure ratio and stability margins.


Author(s):  
Boris Chetverushkin ◽  
Nicola D’Ascenzo ◽  
Sergey Ishanov ◽  
Valeri Saveliev

AbstractThe article presents the developments of the kinetic consistent approach of solution of the magneto gas dynamics problems on the high performance computing systems with massive parallelism. The main idea is to derive the magneto gas dynamic equations from the Boltzmann equation using a complex distribution function, including the electromagnetic terms. The derived equations were used for the formulation of the explicit numerical method of solution for the high performance parallel computing systems. The numerical experiments were performed for the verification of the chosen method.


Published data on flat grid purges allow to evaluate the efficiency of blade devices with different kinematic scheme of stages and design parameters. The authors present the main provisions of the calculation program algorithm and some results of numerical analysis of the efficiency of flat grids of axial stages with different combinations of design parameters. The content of the article and the computer program are addressed to people who are improving their knowledge of gas dynamics of axial compressors. Some of the results may be of interest to specialists working professionally in this field.


1967 ◽  
Vol 31 ◽  
pp. 117-119
Author(s):  
F. D. Kahn ◽  
L. Woltjer

The efficiency of the transfer of energy from supernovae into interstellar cloud motions is investigated. A lower limit of about 0·002 is obtained, but values near 0·01 are more likely. Taking all uncertainties in the theory and observations into account, the energy per supernova, in the form of relativistic particles or high-velocity matter, needed to maintain the random motions in the interstellar gas is estimated as 1051·4±1ergs.


Author(s):  
Douglas L. Dorset ◽  
Barbara Moss

A number of computing systems devoted to the averaging of electron images of two-dimensional macromolecular crystalline arrays have facilitated the visualization of negatively-stained biological structures. Either by simulation of optical filtering techniques or, in more refined treatments, by cross-correlation averaging, an idealized representation of the repeating asymmetric structure unit is constructed, eliminating image distortions due to radiation damage, stain irregularities and, in the latter approach, imperfections and distortions in the unit cell repeat. In these analyses it is generally assumed that the electron scattering from the thin negativelystained object is well-approximated by a phase object model. Even when absorption effects are considered (i.e. “amplitude contrast“), the expansion of the transmission function, q(x,y)=exp (iσɸ (x,y)), does not exceed the first (kinematical) term. Furthermore, in reconstruction of electron images, kinematical phases are applied to diffraction amplitudes and obey the constraints of the plane group symmetry.


TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.


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