... to the redesign of a single rotor row and two double-stage axial fans. The departure angles and work distributions in the inverse design were taken as design variables separately in optimizations of the single rotor and double-stage fans, and they were parametrically represented by means of Bézier curves, whose...

...R. Srivastava; J. Panovsky; R. Kielb; L. Virgin; K. Ekici A new mechanism for fan stator vane failure in turbofan engines at high speed and high loading has been identified and reported in this paper. Highly destructive vane failures have been encountered at Honeywell in a development fan...

... , R. , 2007 , “ Numerical Simulation of Counter-Rotating Fan Aeroacoustics ,” AIAA Paper No. 2007-3680. Stuermer , A. , and Yin , J. , 2009 , “ Low-Speed Aerodynamics and Aeroacoustics of CROR Propulsion Systems ,” AIAA Paper No. 2009-3134. Hanson , D. , and Parzych , D...

...Mehdi Vahdati; George Simpson; Mehmet Imregun This paper describes a detailed wide-chord fan blade flutter analysis with emphasis on flutter bite. The same fan was used with three different intakes of increasing complexity to explain flutter mechanisms. Two types of flutter, namely, stall...

... hole geometries: simple angled (axial angle of 30 deg) and compound angled (axial angle of 30 deg and compound angle of 45 deg) and cylindrical and fan-shaped film-cooling holes. Each plate considered has seven holes, each hole 4 mm in diameter. The plates with cylindrical holes have a spacing of 3...

...Sébastien Lemire; Huu Duc Vo This paper proposes a new technique to reduce the noise generated by rotor-stator interaction (tonal noise) in fans and compressors. The method involves the use of single dielectric barrier discharge (plasma) actuators near the blade trailing edge to reduce blade wakes...

... characterization capability and suitable tools/rules for the design of distortion tolerant engines. This paper describes efforts to establish a high-fidelity prediction capability of distortion transfer and fan response via high-performance computing. The current CFD capability was evaluated with a focus...

...Jixian Yao; Steven E. Gorrell; Aspi R. Wadia Part I of this paper validated the ability of the unsteady Reynolds-Averaged Navier-Stokes (RANS) solver PTURBO to accurately simulate distortion transfer and generation through selected blade rows of two multistage fans. In this part, unsteady RANS...

...Dilip Prasad; Wesley K. Lord The flow through a high-bypass ratio fan stage during engine-out conditions is investigated, with the objective of quantifying the internal losses when the rotor is at “windmill.” An analysis of altitude test data at various simulated flight Mach numbers shows...

...Alessandro Corsini; Franco Rispoli; A. G. Sheard This paper reports on quantitative tests of passive techniques for rotor-tip noise control in low-speed axial flow fans, based on blade-tip modifications involving the addition of antivortex appendages as end-plates. The end-plate thickness chordwise...

...Juan Du; Feng Lin; Hongwu Zhang; Jingyi Chen A numerical investigation on the self-induced unsteadiness in tip leakage flow is presented for a transonic fan rotor. NASA Rotor 67 is chosen as the computational model. It is found that under certain conditions the self-induced unsteadiness can...

...Nobuyuki Yamaguchi; Masayuki Ogata; Yohei Kato An improved construction of air-separator device, which has radial-vanes embedded within its inlet circumferential opening with their leading-edges facing the moving tips of the fan rotor-blades so as to scoop the tip flow, was investigated...

...Nobuyuki Yamaguchi; Masayuki Ogata; Yohei Kato The stall-prevention effect of air separators incorporating radial vanes in place of the existing axial vanes was investigated on a low-speed, single-stage, lightly loaded axial-flow fan for effective and compact air separators of a simplified...

... computational fluid dynamics fans flow instability flow separation transonic flow vortices wakes As part of an ongoing effort to increase stage loading and efficiency, the Air Force Research Laboratory (AFRL), Compressor Aero Research Laboratory (CARL), has been conducting experimental...

... to the design of a generic turbofan core compression system is introduced. It is shown that nearly one percentage point of the equivalent compressor adiabatic efficiency can be saved. 27 06 2008 25 07 2008 20 04 2009 aerodynamics compressors design engineering fans turbomachinery...

...James S. Porter; Jane E. Sargison; Gregory J. Walker; Alan D. Henderson This study presents velocity and turbulence data measured experimentally in the near field of a round and a laterally expanded fan-shaped cooling hole. Both holes are fed by a plenum inlet, and interact with a turbulent...

...A. R. Wadia; P. N. Szucs This paper reports on the numerical assessment of the differences in aerodynamic performance between part span shrouded and unshrouded fan blades generally found in the first stage of multistage fans in low bypass ratio aircraft engines. Rotor flow fields for both blade...

...Markus Tremmel; Dale B. Taulbee Radial fans of the squirrel-cage type are used in various industrial applications. The analysis of such fans via computational fluid mechanics can provide the overall fan performance coefficients, as well as give insights into the detailed flow field. However...

...Jack L. Kerrebrock; Alan H. Epstein; Ali A. Merchant; Gerald R. Guenette; David Parker; Jean-Francois Onnee; Fritz Neumayer; John J. Adamczyk; Aamir Shabbir The design and test of a two-stage, vaneless, aspirated counter-rotating fan is presented in this paper. The fan nominal design objectives...

..., will be quiet relative to current turbofans. To reduce the engine weight, a system with a gearbox, or some other form of shaft speed reduction device, is proposed. This is combined with a low-speed fan and a turbine with high gap-chord spacing to further reduce turbomachinery source noise. An engine...