Two-fluid model for simulation of supersonic flow of wet steam within high-pressure nozzles

Ahmadpour

Applied Thermal Engineering

et al. 2017

Self Cite

Highlights• CFD-based shape optimization of a nozzle and a turbine blade regarding nucleating steam flow is performed.• Nucleation rate and droplet radius are the best suited objective functions for the optimization p rocess.• Maximum 34% reduction in entropy generation rate is reported for turbine cascade.• A maximum 10% reduction in Baumann factor and a maximum 2.1% increase in efficiency is achieved for a turbine cascade. Abstract:In this study CFD-based shape optimization of a 3D nozzle and a 2D turbine blade cascade is undertaken in the presence of non-equilibrium condensation within the considered flow channels.A two-fluid formulation is used for the simulation of unsteady, turbulent, supersonic and compressible flow of wet steam accounting for relevant phase interaction between nucleated liquid droplets and continuous vapor phase. An in-house CFD code is developed to solve the governing equations of the two phase flow and was validated against available experimental

“…According to the condensation model adopted here (Eqs. [12][13][14][15][16][17][18], the phase change is represented by two mass sources:…”

Section: Non-equilibrium Condensation Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

Ahmadpour

Applied Thermal Engineering

et al. 2017

Self Cite

Sci. Sin.-Phys. Mech. Astron.

“…采用拉格朗日方法一般需要巨大的计算量, 相比之下采用欧拉方法来描述微粒运动所需计算量就要小很多. Wu等人 [11] 和Dykas 等人 [12] 对汽轮机叶片附近的湿蒸气流动的研究, 以及 Dykas等人 [13] 和Abadi等人 [14] 对跨音速和超音速喷管中的湿蒸气流动研究都采用了欧拉方法, 即把液滴微粒当作分布于承载气体中的弥散相, 考虑微粒的对流扩散. Hulburt等人 [15] 于1964年从经典力学角度引入了矩方法, 并用此方法讨论湿蒸气中液滴的凝结增长问题.…”

Section: 引言unclassified

The slip effect of micro-droplets in Rankine vortex

Xie¹,

Cao²,

Qin³

et al. 2017

Micro-Raman investigations on the structures of the surface and the inner of MgSO 4 droplets Chinese Science Bulletin 53, 2414 (2008); Measurement of the association constants through micro-Raman spectra of supersaturated lithium perchlorate droplets SCIENCE CHINA Chemistry 56, 1633 (2013); Experimental study of a micro-scale solar organic Rankine cycle system based on compound cylindrical Fresnel lens solar concentrator SCIENCE CHINA Technological Sciences 62, 2184 (2019); Effect of charge on growth of droplets with ionic condensation nuclei Chinese Science Bulletin 56, 1942 (2011); Continuum-based slip model and its validity for micro-channel flows

Proceedings of the Institution of Mechanical Engineers, Part G:

“…Noori Rahim Abadi et al. 13 presented a two-fluid simulation of supersonic flow within high-pressure nozzles with a nonequilibrium phase change. The simulation is carried out to predict the flow characteristics within high-pressure nozzles by CFD code.…”

Section: Introductionmentioning

confidence: 99%

Performance improvement of supersonic nozzles design using a high-temperature model

Hamaidia

Zebbiche

Sellam

et al. 2019

The aim of this paper is to discuss the development of new contours of axisymmetric supersonic nozzles giving a uniform and parallel flow at the exit section, to improve the aerodynamic performances compared to the minimum length nozzle, by increasing the exit Mach number and the thrust coefficient, and by reduction of the nozzle's mass, while holding the same throat section between the two nozzles. The new nozzle is named the best performance nozzle. Its form contains a cylindrical central body and an external wall for the flow redress. The study is done at high temperature, lower than the dissociation threshold of the molecules. The variation of the specific heats with the temperature is considered. The design is made by the method of characteristics. The predictor-corrector algorithm is used to make the numerical resolution of the obtained nonlinear algebraic equations. The validation of results is made by the convergence of the numerical critical sections ratio with that given by the theory. The comparison of the results is made with the minimum length nozzle since it is currently used in the aerospace propulsion. The design depends on M E, T0, y body, y*, and the mesh generation. The application is done with air. A computational fluid dynamics verification for the under nozzle expressed regime has shown that a flow separation with the wall is observed because of the side-loads, which are reduced for this new nozzle compared to the minimum length nozzle.