Development of High Efficiency Propeller Fan for Heat-Pump Unit Using CFD and Numerical Optimization

2011 ◽  
Author(s):  
Hironobu Yamakawa ◽  
Taku Iwase ◽  
Shigehisa Funabashi ◽  
Kouichi Sakamoto ◽  
Yutaka Enokizu ◽  
...  
Keyword(s):  
Numerical Optimization ◽  
Flow Model ◽  
High Efficiency ◽  
Optimization Techniques ◽  
Aerodynamic Noise ◽  
Navier Stokes ◽  
Objective Functions ◽  
Fan Noise ◽  
Heat Pump Unit ◽  
Computational Fluid Dynamics Cfd

We developed a high-efficiency propeller fan to reduce electric power consumption of the fan motor for outdoor heatpump units, and we developed a designing tool combining computational fluid dynamics (CFD) with multi-objective optimization techniques based on the genetic algorithm (GA). In CFD, a numerical model is calculated using commercial software based on steady state, Reynolds-averaged Navier-Stokes (RANS) and k-ε turbulent flow model. The objective functions are fan efficiency and fan noise for optimization. Fan efficiency is calculated directly from the CFD results, and fan noise is calculated using an aerodynamic noise prediction model using the relative inlet and outlet velocities of the fan blades from the CFD results. We fabricated a high-efficiency propeller fan characterized with curled trailing edge tips from Pareto optimal solutions. The experimental results from the performance of the fan showed the developed fan was more efficient than conventional fan.

Development of High-Efficiency Half-Ducted Propeller Fan for Packaged Air Conditioners

2014 ◽  
Author(s):  
Taku Iwase ◽  
Tetsushi Kishitani
Keyword(s):  
Noise Level ◽  
High Efficiency ◽  
Static Pressure ◽  
Suction Side ◽  
Design Tool ◽  
Optimization Techniques ◽  
Aerodynamic Noise ◽  
Air Conditioner ◽  
Fan Noise ◽  
Ducted Propeller

We developed a high-efficiency half-ducted propeller fan to reduce the electric power consumption of the outdoor unit of a packaged air conditioner by using a design tool combining computational fluid dynamics (CFD) with multi-objective optimization techniques based on a genetic algorithm (GA). The baseline fan was a half-ducted propeller fan with three blades of a currently available product. Blade shape was defined using 16 design variables including inlet and outlet blade angles, setting angles, blade length, sweep angles, dihedral angles, and so on. An in-house program was used to automatically generate the grids for CFD calculation. The objective functions were static pressure efficiency and fan noise level for optimization. The fan noise was calculated with an aerodynamic noise prediction model that used the relative inlet and outlet velocities of the fan blades from the CFD results. We found there was a trade-off relationship between the static pressure efficiency and the fan noise. We then selected the optimized fan that had the same noise level as the baseline fan but with an improved static pressure efficiency. The blade tip of the optimized fan was curled toward the suction side direction. Finally, we confirmed through experiments that the static pressure efficiency of the optimized fan was increased by 1.6% compared to the baseline fan.

Development of Autonomous Design Technique for Axial Fans Using Numerical Optimization

2005 ◽  
Author(s):  
Taku Iwase ◽  
Kazuyuki Sugimura ◽  
Taro Tanno
Keyword(s):  
Numerical Optimization ◽  
Simulated Annealing Algorithm ◽  
Static Pressure ◽  
Pressure Rise ◽  
Navier Stokes ◽  
Axial Fan ◽  
Automatic Program ◽  
Axial Fans ◽  
Computational Fluid Dynamics Cfd ◽  
Annealing Algorithm

We designed an axial fan for servers using computational fluid dynamics (CFD) and numerical optimization. The performance of the fan, namely static pressure rise and efficiency, was calculated using commercial CFD software based on an incompressible Reynolds-averaged Navier-Stokes (RANS) solver. An automatic program developed in-house was used to generate the grids for CFD calculation. Numerical optimization—using a simulated annealing algorithm (SA)—was used for determining the optimized shape of the fan. After optimizing the fan, initial and optimized fan designs were made for experiments using rapid prototyping, and their performances, based on such things as efficiency and noise level, were measured. Results demonstrated that the optimized fan design achieved higher efficiency than the initial design. Multi optimization was also developed for maximizing the fan efficiency and minimizing the casing height. An additional finding was that there was a trade-off between the fan efficiency and casing height.

Optimal Design for Impeller of a Sludge Pump Using Design of Experiment

2019 ◽  
Author(s):  
Jeong-Min Jin ◽  
Hyo-Geun Ji ◽  
Youn-Jea Kim
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Design Of Experiment ◽  
Design Theory ◽  
Flow Analysis ◽  
Optimization Techniques ◽  
Navier Stokes ◽  
Pump Impeller ◽  
Computational Fluid Dynamics Cfd ◽  
Design Factors

Abstract Recently, many studies carried out to improve the performance of the pump with shape changes. In this paper, impeller optimization is performed to improve the pump performance. Design optimization techniques for the sludge pump impellers have been developed by using computational fluid dynamics (CFD) and optimal design theory. This paper describes the design optimization of a sludge pump impeller based on Response Surface Method (RSM) coupled with Navier-Stokes flow analysis. In particular, RSM which was based on the results of the design of experiment (DOE) helps to achieve the optimum point. In order to optimize the shape of the impeller, the thickness and the height of the blade were set as design factors. As a result, it was confirmed that the efficiency and the head were improved by 11.2% and 6.67%, respectively, compared to the referenced model.

Advanced Numerical Methods for the Prediction of Tonal Noise in Turbomachinery—Part II: Time-Linearized Methods

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Christian Frey ◽  
Graham Ashcroft ◽  
Hans-Peter Kersken ◽  
Christian Weckmüller
Keyword(s):  
Boundary Condition ◽  
Linear System ◽  
Near Field ◽  
Linear Equations ◽  
Time Integration ◽  
Aerodynamic Noise ◽  
Fan Noise ◽  
Rotor Stator Interaction ◽  
Complex Linear ◽  
Computational Fluid Dynamics Cfd

This is the second part of a series of two papers on unsteady computational fluid dynamics (CFD) methods for the numerical simulation of aerodynamic noise generation and propagation. It focuses on the application of linearized RANS methods to turbomachinery noise problems. The convective and viscous fluxes of an existing URANS solver are linearized and the resulting unsteady linear equations are transferred into the frequency domain, thereby simplifying the solution problem from unsteady time-integration to a complex linear system. The linear system is solved using a parallel, preconditioned general minimized residual (GMRES) method with restarts. In order to prescribe disturbances due to rotor stator interaction, a so-called gust boundary condition is implemented. Using this inhomogeneous boundary condition, one can compute the generation of the acoustic modes and their near field propagation. The application of the time-linearized methods to a modern high-bypass ratio fan is investigated. The tonal fan noise predicted by the time-linearized solver is compared to numerical results presented in the first part and to measurements.

High-efficiency design of a tunnel ventilation jet fan through numerical optimization techniques

2012 ◽  
Vol 26 (6) ◽  
pp. 1793-1800 ◽  
Author(s):  
Joon-Hyung Kim ◽  
Jin-Hyuk Kim ◽  
Kwang-Yong Kim ◽  
Joon-Yong Yoon ◽  
Sang-Ho Yang ◽  
...  
Keyword(s):  
Numerical Optimization ◽  
High Efficiency ◽  
Optimization Techniques ◽  
Tunnel Ventilation ◽  
Jet Fan

Design Optimization of Axial Flow Compressor Blades With Three-Dimensional Navier-Stokes Solver

2000 ◽  
Author(s):  
Sang-Yun Lee ◽  
Kwang-Yong Kim
Keyword(s):  
Numerical Optimization ◽  
Golden Section ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Optimization Techniques ◽  
Search Direction ◽  
Navier Stokes ◽  
Optimum Shape ◽  
Optimization Search

Numerical optimization techniques combined with a three-dimensional thin-layer Navier-Stokes solver are presented. The techniques are used to find an optimum shape of a stator blade in an axial compressor through calculations of single stage rotor-stator flow. The Baldwin-Lomax model is chosen to describe turbulence. For the numerical optimization, search direction is calculated using the steepest decent method and the conjugate direction method. The golden section method is used to determine optimum moving distance along the search direction. The object of the present optimization is to maximize the efficiency. An optimum stacking line is found which produces a custom-tailored three-dimensional blade design.

scholarly journals CFD Investigation on Hydrodynamic Resistance of a Novel Subsea Shuttle Tanker

2021 ◽  
Vol 9 (12) ◽  
pp. 1411
Author(s):  
Yihan Xing ◽  
Marek Jan Janocha ◽  
Guang Yin ◽  
Muk Chen Ong
Keyword(s):  
High Efficiency ◽  
Navier Stokes ◽  
Hydrodynamic Resistance ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
Large Eddy ◽  
Computational Fluid Dynamics Cfd ◽  
Carbon Dioxide Co2 ◽  
Subsea Pipelines

The Subsea Shuttle Tanker (SST) was proposed by Equinor as an alternative to subsea pipelines and surface tankers for the transportation of liquid carbon dioxide (CO2) from existing offshore/land facilities to marginal subsea fields. In contrast to highly weather-dependent surface tanker operations, the SST can operate in any condition underwater. Low resistance is paramount to achieving maximum range. In this paper, the resistance of the SST at an operating forward speed of 6 knots (3.09 m/s) and subject to an incoming current velocity of 1 m/s is computed using Computational Fluid Dynamics (CFD). The Delayed Detached Eddy Simulation (DDES) method is used. This method combines features of Reynolds-Averaged Navier–Stokes Simulation (RANS) in the attached boundary layer parts at the near-wall regions, and Large Eddy Simulation (LES) at the unsteady, separated regions near to the propeller. The force required to overcome forward resistance is calculated to be 222 kN and agrees well with experimental measurements available in the open literature. The corresponding power consumption is calculated to be 927 kW, highlighting the high efficiency of the SST. The method presented in this paper is general and can be used for resistance optimization studies of any underwater vessel.

scholarly journals Nondimensional Characterization of the Operational Envelope of a Wet Friction Clutch

Computation ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 21 ◽  
Author(s):  
Nikolaos Rogkas ◽  
Christos Vakouftsis ◽  
Georgios Vasileiou ◽  
Christos Manopoulos ◽  
Vasilios Spitas
Keyword(s):  
High Efficiency ◽  
Computational Cost ◽  
Relative Weight ◽  
Navier Stokes ◽  
Operational Conditions ◽  
Wet Friction ◽  
Wet Clutch ◽  
Computational Fluid Dynamics Cfd ◽  
Operational Envelope

In recent years, multidisc wet friction clutches are used in demanding powertrains of automatic and dual clutch transmissions targeting high efficiency and smoothness during gearshift. However, the developed flow pattern between the clutch discs is significantly complex and the Computational Fluid Dynamics (CFD) methods employed are quite demanding in terms of computational cost. To deal with this issue semi-analytical solutions were derived, which are limited, however, to specific problems, in order to obtain handy expressions, while also providing insight to the wet clutch physics. Nevertheless, this lack of global validity is counterbalanced by the fact that the governing equations become analytically solvable at specific operational conditions with satisfactory accuracy, provided that the simplifications rendering the truncated terms inactive hold true. In this work, a quantitative way of determining the relative weight of each term of the Navier-Stokes (NS) equations set is presented, based on the post-processing of CFD results using the Buckingham “π-theorem”. The sets of nondimensional numbers created were used to describe and model the physics of the wet clutch.

scholarly journals Estimation of aerodynamic noise of diaphragms through IEC 60534-8-3 and CFD

2021 ◽  
pp. 002029402198976
Author(s):  
Luca Fenini ◽  
Luca Nicola Quaroni ◽  
Stefano Malavasi
Keyword(s):  
Stokes Equations ◽  
Mechanical Energy ◽  
Power Level ◽  
Acoustic Power ◽  
Acoustic Energy ◽  
Orifice Plate ◽  
Aerodynamic Noise ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Computational Fluid Dynamics Cfd

The aerodynamic noise emitted by a subsonic flow of dry air through an orifice plate is estimated in terms of internal sound power level and external sound pressure level (SPL) by application of the methodology described in the international standard IEC 60534-8-3. A shortcoming of the standard in defining the efficiency of the transformation of the mechanical energy of the flow into acoustic energy is discussed. Experimental evidence of the matter is also described. An alternative model employing the resolution of Reynolds Averaged Navier-Stokes equations (RANS) by means of Computational Fluid Dynamics (CFD) techniques for the calculation of the acoustic power generated by the turbulent flow through the orifice plate is applied so as to overcome the issue.

Analysis of the Automobile’s External Aerodynamic Noise Field Characteristics Based on CAA

2011 ◽  
Vol 130-134 ◽  
pp. 58-62 ◽  
Author(s):  
Zheng Yu Zheng ◽  
Ren Xian Li
Keyword(s):  
Fluid Dynamics ◽  
Boundary Condition ◽  
Computational Fluid Dynamics ◽  
Flow Model ◽  
Noise Source ◽  
Aerodynamic Noise ◽  
Dipole Source ◽  
Noise Field ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Pressure

This paper dwelled on the principle of Computational Aero-Acoustics (CAA), and utilized the Boundary Element Method (BEM) combined with the Computational Fluid Dynamics (CFD) based on Lighthill’s analogy to the automobile flow model, and converted the fluctuating flow pressure near the vehicle’s surface into the dipole source boundary condition in acoustics grid, and eventually succeeded in simulating the external aerodynamic noise field of automobile by introducing the dipole source boundary condition into the automobile’s BEM model. The distribution of vehicle’s external aero-acoustics field and the directivity of vehicle’s surface aerodynamic acoustic dipole source were also discussed carefully in this paper. The results show that: The head and tail of car are the main aerodynamic noise source radiation areas, and most of the dipole source’s SPL value is more than 70dB; the variation in car speed greatly impacts on the directivity of aerodynamic noise field near the car’s tail surface (θ=165°~195°).

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