Energy Efficient Single Stage Axial Fan (ENEF)

2007 ◽  
Author(s):  
C. D. Pitis
Keyword(s):  
Energy Efficient ◽  
Single Stage ◽  
Axial Fan

scholarly journals Energy-Efficient Single-Stage Nitrite Shunt Denitrification with Saline Sewage through Concise Dissolved Oxygen (DO) Supply: Process Performance and Microbial Communities

2020 ◽  
Vol 8 (6) ◽  
pp. 919 ◽  
Author(s):  
Huichuan Zhuang ◽  
Zhuoying Wu ◽  
Linji Xu ◽  
Shao-Yuan Leu ◽  
Po-Heng Lee
Keyword(s):  
Dissolved Oxygen ◽  
Microbial Communities ◽  
Energy Efficient ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Single Stage ◽  
Rrna Gene ◽  
Unexpected Finding ◽  
Sequencing Analysis ◽  
Ratio Requirement

Single-stage nitrite shunt denitrification (through nitrite rather than nitrate) with low dissolved oxygen (DO) supply is a better alternative in terms of energy-efficiency, short-footprint, and low C/N-ratio requirement. This study investigates the optimal DO level with temperature effect, with saline sewage at the fixed hydraulic and solids retention times of 8 h and 8 d, respectively. Moreover, 16S rRNA gene sequencing analysis corresponding with total nitrogen (TN) and chemical oxygen demand (COD) removals in each operating condition were performed. Results showed that DO of 0.3 mg/L at 20 °C achieved over 60.7% and over 97.9% of TN and COD removal, respectively, suggesting that such condition achieved effective nitrite-oxidizing bacteria inhibition and efficient denitrification. An unexpected finding was that sulfur-reducing Haematobacter and nitrogen-fixing Geofilum and Shinella were highly abundant with the copredominance of ammonia-oxidizing Comamonas and Nitrosomonas, nitrite-oxidizing Limnohabitans, and denitrifying Simplicispira, Castellaniella, and Nitratireductor. Further, canonical correspondence analysis (CCA) with respect to the operating conditions associated with phenotype prediction via R-based tool Tax4Fun was performed for a preliminary diagnosis of microbial functionality. The effects of DO, temperature, nitrite, and nitrate in various extents toward each predominant microbe were discussed. Collectively, DO is likely pivotal in single-stage nitrite shunt denitrification, as well as microbial communities, for energy-efficient saline sewage treatment.

scholarly journals Results From Tests on a High Work Transonic Turbine for an Energy Efficient Engine

1980 ◽  
Author(s):  
D. E. Crow ◽  
M. R. Vanco ◽  
H. Welna ◽  
I. D. Singer
Keyword(s):  
Energy Efficient ◽  
Expansion Ratio ◽  
Single Stage ◽  
Advanced Technology ◽  
Aerodynamic Efficiency ◽  
Turbofan Engines ◽  
Engine Design ◽  
Transonic Turbine ◽  
New Generation ◽  
High Work

This paper will present the experimental results of the evaluation of two high work, transonic, single-stage turbines investigated under the Energy Efficient Engine Program. The objective of the E3 program, a joint P&WA/NASA program (NAS3-20646) is to provide an advanced technology base for a new generation of fuel-conservative turbofan engines. A single-stage turbine required fewer cooled airfoils, a reduced number of leakage paths and no interstage seals. These advanced energy efficient engines require high engine pressure ratios resulting in high expansion ratio, transonic, turbine designs which must have high aerodynamic efficiency. The goal of the turbine program is to develop a high pressure turbine that is compatible with the overall engine design and has an uncooled efficiency of 90.8 percent.

Aerodynamic and Acoustic Performance of a Single Stage Axial Fan With Extensive Blade Sweep Designed to Limit Noise Emissions

2016 ◽  
Author(s):  
Daniel Giesecke ◽  
Jens Friedrichs ◽  
Udo Stark ◽  
Maik Dierks
Keyword(s):  
Axial Flow ◽  
Leading Edge ◽  
Vital Role ◽  
Single Stage ◽  
Numerical Verification ◽  
Axial Fan ◽  
Trailing Edge ◽  
Sweep Angle ◽  
Acoustic Performance ◽  
Versatile Tool

Not only the aerodynamic performance of axial flow fans is important but also the acoustic behaviour plays a vital role. It is to be expected that in the future noise limits will be more regulated by legislation. The aim of this project is to develop a very versatile tool for efficient and noise reduced axial flow fans in rotor / stator configuration. This paper describes the design, numerical verification and tests of a highly loaded single stage axial flow fan making use of extensive blade sweep in rotor and stator for acoustic reasons. The tests include aerodynamic and acoustic investigations. The stage is a conventional free vortex design with unconventional blades of a special planform. The blade sections of both rotor and stator are NACA 65-sections on circular arc mean lines. Sectional diffusion factors and de Haller numbers are close to their respective limits, especially for the sections next to the rotor and stator hubs. The rotor is characterised by a forward-swept leading edge with increasing sweep angle towards hub and tip and an unswept trailing edge. The leading edge of the stator blades is forward-swept as before but this time at an almost constant sweep angle between the hub and the two-thirds position of the blade span. The trailing edge is straightened for reducing the previously mentioned aerodynamic loadings. The study shows that the numerical results are consistent with the experimental outcome. It concludes that the advanced design features show potential aerodynamic and acoustic benefits by sweeping the blade in the described manner. This is particularly the case when comparing to single row designs.

Experimental Investigation of the Effect of Reynolds Number on the Efficiency of Single-Stage Axial Fans

2018 ◽  
Author(s):  
Massimo Masi ◽  
Stefano Castegnaro ◽  
Andrea Lazzaretto
Keyword(s):  
Reynolds Number ◽  
Axial Flow ◽  
Operating Conditions ◽  
Single Stage ◽  
Axial Fan ◽  
Low Speed ◽  
Surface Finishes ◽  
Axial Fans ◽  
The Many ◽  
Testing Standards

Uncertainties surrounding the influence of Reynolds number on the performance of air handling turbomachines are as old as the study of turbomachinery fluid dynamics. In particular, all low-speed turbomachines and most axial-flow fans feature Reynolds numbers that are often lower than the critical value, above which the literature states a limited dependency of blades cascade aerodynamics on Reynolds number. Testing standards already account for this well-known issue, which arises mainly in the case of geometrically similar fans of different size and/or operating conditions. On the other hand, one of the main practical issues in the design of low-speed machines is the disagreement among the most authoritative sources on the value of the critical Reynolds number for axial fans. The many definitions of Reynolds number, which are suited to either fan design purposes or fan performance assessment, introduce additional problems, as the corresponding values may differ by orders of magnitude depending on the chosen definition. A less debated issue deals with the effect of Reynolds number on global performance and efficiency parameters for different axial-flow fan configurations. This paper reports pressure and efficiency data measured at several rotational speeds of four axial fans that feature different configurations, hub-to-tip ratios, sizes and surface finishes. In particular, the tests consider two 315mm and one 630mm tube-axial fans, and one 800mm vane-axial fan with preswirler blading. Data on two vane-axial fans with straightener, and one preswirler-rotor-stator stage, available in the literature, widen the discussion on the Reynolds number effect on the entire category of single-stage axial fans.

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