امیر نجات
دانشکده مهندسی مکانیک، دانشگاه تهران
[ 1 ] - بررسی تاثیر افزایش فشار کندانسور بر کارایی مراحل کم فشار توربین بخار به کمک شبیه سازی عددی
افزایش فشار کندانسور مستقیماً بر عملکرد توربین بخار تأثیر خواهد داشت. برای بررسی این تغییرات، می‌توان از شبیه‌سازی عددی توربین بخار و تحلیل رفتار آن، به‌عنوان یک راهکار کاربردی استفاده کرد. در این پژوهش تلاش شده تمامی هفت مرحله ناحیه‌ی کم‌فشار توربین بخار توسط نرم‌افزار ANSYS-CFX به‌صورت سه‌بعدی و پایا شبیه‌سازی و تحلیل شود. برای اطمینان از صحت نتایج، نتایج به‌دست‌آمده با نتایج حاصل از اند...
[ 2 ] - Optimization of turbine blade cooling with the aim of overall turbine performance enhancement
In the current work, different methods for optimization of turbine blade internal cooling are investigated, to achieve higher cyclic efficiency and output power for a typical gas turbine. A simple two-dimensional model of C3X blade is simulated and validated with available experimental data. The optimization process is performed on this model with two different methods. The first method is ...
[ 3 ] - Aerodynamic optimization of a 5 Megawatt wind turbine blade
Wind power has been widely considered in recent years as an available and a clean renewable energy source. The cost of wind energy production is currently the main issue, and increasing the size of wind turbines can reduce wind energy production costs. Hence, megawatt wind turbines are being rapidly developed in recent years. In this paper, an aerodynamic analysis of the NREL 5MW turbine is...
[ 4 ] - The parametric study of an electrical submersible pump rotary gas separator under two-phase flow condition
The performance of the electric submersible pump (ESP) significantly affected by Gas Void Fraction (GVF). Thus, using of a Rotary Gas Separator (RGS) is a suitable solution for this issue. The performance of the RGS is function of different parameters such as geometry of impeller, rotating speed, boundary conditions, media viscosity and GVF. In this study, the influences of GVF, viscosity, ...
[ 5 ] - Numerical aeroelastic analysis of wind turbine NREL Phase VI Rotor
This study investigated the performance and aeroelastic characteristics of a wind turbine blade based on strongly coupled approach (two-way fluid structure interaction) to simulate the transient FSI[1] responses of HAWT[2]. Aerodynamic response was obtained by 3D CFD-URANS approach and structural response was obtained by 3D Finite element method. ...
[ 6 ] - A robust engineering approach for wind turbine blade profile aeroelastic computation
Wind turbines are important devices that extract clean energy from wind flow. The efficiency of wind turbines should be examined under various working conditions in order to estimate off-design performance. Numerous aerodynamic and structural research works have been carried out to compute aeroelastic effects on wind turbines. Most of them suffer from either the simplicity of the modelling ...
[ 7 ] - Assessment of various rotor tip geometries on a single stage gas turbine performance
Tip leakage loss introduces major part of losses of the rotor in axial gas turbines. Therefore, the rotor blade tip has a considerable effect on rotor efficiency. To understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). Various blade tip configurations s...
[ 8 ] - Numerical investigation of clocking in a two-stage gas turbine
Flow in the first two-stage of V 94.2 gas turbine is simulated numerically. In this turbine, the second stator is clocked relative to the first stator to different positions. Steady-state analysis was carried out by varying the circumferential relative position of the consecutive stator vanes to study the effects of the clocking on turbine performance. A density based compressible inviscid ...
[ 9 ] - Aerodynamic Noise Computation of the Flow Field around NACA 0012 Airfoil Using Large Eddy Simulation and Acoustic Analogy
The current study presents the results of the aerodynamic noise prediction of the flow field around a NACA 0012 airfoil at a chord-based Reynolds number of 100,000 and at 8.4 degree angle of attack. An incompressible Large Eddy Simulation (LES) turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is performed by the Ffowcs Williams and Hawkings (FW-...
[ 10 ] - Optimization of turbine blade cooling with the aim of overall turbine performance enhancement
In the current work, different methods for optimization of turbine blade internal cooling are investigated, to achieve higher cyclic efficiency and output power for a typical gas turbine. A simple two-dimensional model of C3X blade is simulated and validated with available experimental data. The optimization process is performed on this model with two different methods. The first method is ...
[ 11 ] - Aerodynamic optimization of a 5 Megawatt wind turbine blade
Wind power has been widely considered in recent years as an available and a clean renewable energy source. The cost of wind energy production is currently the main issue, and increasing the size of wind turbines can reduce wind energy production costs. Hence, megawatt wind turbines are being rapidly developed in recent years. In this paper, an aerodynamic analysis of the NREL 5MW turbine is...
[ 12 ] - The parametric study of an electrical submersible pump rotary gas separator under two-phase flow condition
The performance of the electric submersible pump (ESP) significantly affected by Gas Void Fraction (GVF). Thus, using of a Rotary Gas Separator (RGS) is a suitable solution for this issue. The performance of the RGS is function of different parameters such as geometry of impeller, rotating speed, boundary conditions, media viscosity and GVF. In this study, the influences of GVF, viscosity, and ...
[ 13 ] - Numerical aeroelastic analysis of wind turbine NREL Phase VI Rotor
This study investigated the performance and aeroelastic characteristics of a wind turbine blade based on strongly coupled approach (two-way fluid structure interaction) to simulate the transient FSI1 responses of HAWT2. Aerodynamic response was obtained by 3D CFD-URANS approach and structural response was obtained by 3D Finite element method. Aeroelastic responses of the blade were obtained by ...
[ 14 ] - A robust engineering approach for wind turbine blade profile aeroelastic computation
Wind turbines are important devices that extract clean energy from wind flow. The efficiency of wind turbines should be examined under various working conditions in order to estimate off-design performance. Numerous aerodynamic and structural research works have been carried out to compute aeroelastic effects on wind turbines. Most of them suffer from either the simplicity of the modelling appr...
Co-Authors