The high density of servers in datacenters generates a large amount of heat, resulting in the high possibility of thermally anomalous events, i.e. computer room air conditioner fan failure, server fan failure, and workload misconfiguration. As such anomalous events increase the cost of maintaining computing and cooling components, they need to be detected, localized, and classified for taking a...

There has been a growing concern recently about energy use and its adverse impact on the environment. Industrial motor uses a major fraction of total industrial energy uses. Conventional ceiling and table fans have the potential to improve on energy efficiency, but the enhancements described in this research study increase the device’s efficiency further, thereby permitting greater energy savin...

Rotating stalls are generally the first instability met in turbomachinery, before surges. This 3D phenomenon is characterized by one or more stalled flow cells which rotate at a fraction of the impeller speed. The goal of the present work is to shed some light on the entropy generation in a centrifugal fan under rotating stall conditions. A numerical simulation of entropy generation is carried ...

each year, millions of liters of toxic liquid, are used to combat with pests and plant diseases in farms. the wide spread use of chemical pesticides causes great environmental hazards. particles drift is one of the main problems in spraying which results in the contamination of farm lands, humans and animals. management of particle size is regarded as the main factor in drift control. in this s...

In this paper, a HVAC (heating, ventilating and air-conditioning) system has two different zones was designed and fan motor speed to minimize energy consumption of the HVAC system was controlled by a conventional (proportional–integral-derivative) PID controller. The desired temperatures were realized by variable flow-rate by considering the ambient temperature for each zone. The control algori...

As the requirement of low power high performance arithmetic circuits, in this paper we introduced a design of new MT-CMOS domino logic and FTL dynamic logic technique to design adder circuit. The MT-MOS transistors reduce the power dissipation by minimizing sub threshold leakage current in domino logic circuits introduced. The MT-NMOS transistor connected in discharging path of output inverter ...

The need of aeroacoustically highefficient fans requires more detailed investigations of three dimensional effects and separated flow analysis. Comprehensive studies and code validation for fans have shown, that further development especially for the influence of sweep -is necessary. Therefore, two different Navier-Stokes Codes, a lifting surface code and a classical method for 3-D cascade flow...

The effectiveness of half flat tip serrations on reducing fan blade trailing edge noise was investigated using experimental methods. experiments were conducted at an anechoic chamber under different rotating speeds. Numerical simulations performed to investigate the mass flow rate generated by serrated and compared with that baseline fan. results showed overall amount reduction decreased increa...

The paper deals with 21 valid species of the genus Thagria from Guangxi Autonomous Region, China. Eight new species are described and illustrated: T. biprocessa Fan & Dai, sp. nov., T. decussata Fan & Dai, sp. nov., T. irregularis Fan & Dai, sp. nov., T. multispinosa Fan & Dai, sp. nov., T. paramultipars Fan & Li, sp. nov., T. triangula Fan & Li, sp. nov., T. trifasciata Fan & Li, sp. nov. and ...

Back-to-back testing has been done using NASA fan rotor 67 in the Glenn Research Center W8 Axial Compressor Test Facility. The rotor was baseline tested with a normal industrial RMS surface finish of 0.5-0.6 μm (20-24 microinches) at 60, 80 and 100% of design speed. At design speed the tip relative Mach number was 1.38. The blades were then removed from the facility and ultrapolished to a surfa...