Three-dimensional CFD simulation of anaerobic reactions in a continuous packed-bed bioreactor

This paper presents a method for optimizing wavy plate-fin heat exchangers accurately and efficiently. It combines CFD simulation, Radical Basis Functions (RBF) with multi-objective optimization to improve the performance. The optimization of the Colburn factor j and the friction coefficient f is regarded as a multi-objective optimization problem, due to the existence of two contradictory goals. The approximation model was obtained by Radical Basis Functions, and the shape of the heat exchanger was optimized by multi-objective genetic algorithm (MOGA). The optimization results showed that j increased by 17.62% and f decreased by 20.76%, indicating that the heat exchange efficiency was significantly enhanced and the fluid structure resistance reduced. Then, from the aspects of field synergy and tubulence energy, the performance advantage of the optimized structure was further confirmed.

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Analysis of a Virtual Prototype First-Stage Rotor Blade Using Integrated Computer-Based Design Tools

Volume 4: Fatigue and Fracture, Heat Transfer, Internal Combustion Engines, Manufacturing, and Technology and Society ◽

10.1115/esda2006-95257 ◽

2006 ◽

Cited By ~ 1

Author(s):

Michel Arnal ◽

Christian Precht ◽

Thomas Sprunk ◽

Tobias Danninger ◽

John Stokes

Keyword(s):

Heat Transfer ◽

Gas Flow ◽

Thermal Loading ◽

Cfd Simulation ◽

Three Dimensional ◽

Life Assessment ◽

Element Analysis ◽

Pressure Losses ◽

Cooling Channels ◽

Internally Cooled

The present paper outlines a practical methodology for improved virtual prototyping, using as an example, the recently re-engineered, internally-cooled 1st stage blade of a 40 MW industrial gas turbine. Using the full 3-D CAD model of the blade, a CFD simulation that includes the hot gas flow around the blade, conjugate heat transfer from the fluid to the solid at the blade surface, heat conduction through the solid, and the coolant flow in the plenum is performed. The pressure losses through and heat transfer to the cooling channels inside the airfoil are captured with a 1-D code and the 1-D results are linked to the three-dimensional CFD analysis. The resultant three-dimensional temperature distribution through the blade provides the required thermal loading for the subsequent structural finite element analysis. The results of this analysis include the thermo-mechanical stress distribution, which is the basis for blade life assessment.

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Toxicity and recalcitrant compound removal from bleaching pulp plant effluents by an integrated system: anaerobic packed-bed bioreactor and ozone

Water Science & Technology ◽

10.2166/wst.2010.794 ◽

2010 ◽

Vol 61 (1) ◽

pp. 199-205 ◽

Cited By ~ 2

Author(s):

T. R. Chaparro ◽

C. M. Botta ◽

E. C. Pires

Keyword(s):

Pulp Mill ◽

Packed Bed ◽

Ultraviolet Absorption ◽

Integrated System ◽

Packed Bed Bioreactor ◽

Cellulose Pulp ◽

Adsorbable Organic Halides ◽

Organic Halides ◽

Before And After ◽

Absorption Measurements

Effluents originated in cellulose pulp manufacturing processes are usually toxic and recalcitrant, specially the bleaching effluents, which exhibit high contents of aromatic compounds (e.g. residual lignin derivates). Although biological processes are normally used, their efficiency for the removal of toxic lignin derivates is low. The toxicity and recalcitrance of a bleached Kraft pulp mill were assessed through bioassays and ultraviolet absorption measurements, i.e. acid soluble lignin (ASL), UV280, and specific ultraviolet absorption (SUVA), before and after treatment by an integrated system comprised of an anaerobic packed-bed bioreactor and oxidation step with ozone. Furthermore, adsorbable organic halides (AOX) were measured. The results demonstrated not only that the toxic recalcitrant compounds can be removed successfully using integrated system, but also the ultraviolet absorption measurements can be an interesting control-parameter in a wastewater treatment.

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