Design and Performance Evaluation of Four Transonic Compressor Rotors

1971 ◽  
Vol 93 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. P. Gostelow
Keyword(s):  
The Other ◽  
Peak Efficiency ◽  
Design Efficiency ◽  
Circular Arc ◽  
Diffusion Factor ◽  
Transonic Compressor ◽  
Blade Row ◽  
Blade Section ◽  
And Performance ◽  
Blade Element

A set of four compressor rotors was designed as a means of optimizing blade camberline shape in the high-transonic Mach number region. One blade row was designed for a tip diffusion factor of 0.35 with the supersonic camber minimized. The other three blade rows were designed for a tip diffusion factor of 0.45 with tip ratios of supersonic to total camber varying from zero to the value corresponding to a double-circular-arc blade section. Performance maps and blade element data were generated as a result of testing on the four rotors. All rotors exceeded design efficiency and flow at conditions corresponding to design point operation. Operating range, from peak efficiency to stall, is highest in rotors designed for a low tip diffusion factor and which have the minimum amount of supersonic camber.

Evaluation of Flow Field Approximations for Transonic Compressor Stages

1996 ◽  
Author(s):  
Daniel J. Dorney ◽  
Om P. Sharma
Keyword(s):  
Flow Field ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Loosely Coupled ◽  
Transonic Compressor ◽  
Blade Row ◽  
Flow Through ◽  
And Performance ◽  
Computer Resources ◽  
Fully Coupled

The flow through gas-turbine compressors is often characterized by unsteady, transonic and viscous phenomena. Accurately predicting the behavior of these complex multi-blade-row flows with unsteady rotor-stator interacting Navier-Stokes analyses can require enormous computer resources. In this investigation, several methods for predicting the flow field, losses and performance quantities associated with axial compressor stages are presented. The methods studied include, 1) the unsteady fully-coupled blade row technique, 2) the steady coupled blade row method, 3) the steady single blade row technique, and 4) the loosely-coupled blade row method. The analyses have been evaluated in terms of accuracy and efficiency.

Investigation of the Axial Velocity Density Ratio in a High Turning Cascade

1975 ◽  
Author(s):  
H. Starken ◽  
F. A. E. Breugelmans ◽  
P. Schimming
Keyword(s):  
Axial Velocity ◽  
Density Ratio ◽  
Two Dimensional ◽  
Flow Conditions ◽  
Circular Arc ◽  
Blade Row ◽  
Two Dimensional Flow ◽  
Blade Section ◽  
Stator Blade ◽  
Density Ratios

Subsonic cascade tests of a stator blade row are presented. A 48-deg cambered double circular arc blade section has been investigated at different inlet Mach numbers (M1 = 0.5, 0.64, 0.74), different inlet flow angles and various axial velocity density ratios. Optimum cascade performance has been obtained at negative incidence angles and near two-dimensional flow condition. The cascade results are compared with stator tests of the same blade section at corresponding flow conditions.

Experimental Cascade Analysis of a Transonic Compressor Rotor Blade Section

1984 ◽  
Vol 106 (2) ◽  
pp. 288-294 ◽  
Author(s):  
H. A. Schreiber ◽  
H. Starken
Keyword(s):  
Rotor Blade ◽  
Flow Behavior ◽  
Density Ratio ◽  
Axial Flow ◽  
Flow Angle ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Blade Row ◽  
Blade Section ◽  
Transonic Cascade

A transonic compressor rotor blade cascade was tested in order to elucidate the flow behavior in the transonic regime and to determine the performance characteristic in the whole operating range of a rotor blade section. The experiments have been conducted in a transonic cascade wind tunnel, which enables tests even at sonic inlet velocities. The influence of the upstream Mach number between 0.8 and 1.1 and the inlet flow angle between choking and stalling of the blade row was investigated. The effect of the axial velocity density ratio (AVDR) could be studied by applying an endwall suction device. Furthermore, the level of the shock losses was determined from a wake analysis. A final comparison of cascade losses and those of the corresponding rotor blade element shows good agreement which underlines the applicability of the cascade model in the design of axial flow turbomachines.

Experimental Cascade Analysis of a Transonic Compressor Rotor Blade Section

1983 ◽  
Author(s):  
H. A. Schreiber ◽  
H. Starken
Keyword(s):  
Rotor Blade ◽  
Density Ratio ◽  
Axial Flow ◽  
Flow Angle ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Blade Row ◽  
Blade Section ◽  
Transonic Cascade ◽  
Good Agreement

A transonic compressor rotor blade cascade was tested in order to elucidate the flow behaviour in the transonic regime and to determine the performance characteristic in the whole operating range of a rotor blade section. The experiments have been conducted in a transonic cascade wind tunnel, which enables tests even at sonic inlet velocities. The influence of the upstream Mach number between 0.8 and 1.1 and the inlet flow angle between choking and stalling of the blade row was investigated. The effect of the axial velocity density ratio (AVDR) could be studied by applying an endwall suction device. Furthermore the level of the shock losses was determined from a wake analysis. A final comparison of cascade losses and those of the corresponding rotor blade element shows good agreement which underlines the applicability of the cascade model in the design of axial flow turbomachines.

scholarly journals Blade Row Interaction Effects on the Performance of a Moderately Loaded NASA Transonic Compressor Stage

2002 ◽  
Author(s):  
Dale E. Van Zante ◽  
Wai-Ming To ◽  
Jen-Ping Chen
Keyword(s):  
Experimental Data ◽  
Velocity Field ◽  
Interaction Effects ◽  
Operating Conditions ◽  
Laser Doppler Velocimeter ◽  
Compressor Stage ◽  
Peak Efficiency ◽  
Transonic Compressor ◽  
Blade Row ◽  
Blade Row Interaction

Blade row interaction effects on loss generation in compressors have received increased attention as compressor work-per-stage and blade loading have increased. Two dimensional Laser Doppler Velocimeter measurements of the velocity field in a NASA transonic compressor stage show the magnitude of interactions in the velocity field at the peak efficiency and near stall operating conditions. The experimental data are presented along with an assessment of the velocity field interactions. In the present study the experimental data are used to confirm the fidelity of a three-dimensional, time-accurate, Navier Stokes calculation of the stage using the MSU-TURBO code at the peak efficiency and near stall operating conditions. The simulations are used to quantify the loss generation associated with interaction phenomena. At the design point the stator pressure field has minimal effect of the rotor performance. The rotor wakes do have an impact on loss production in the stator passage at both operating conditions. A method for determining the potential importance of blade row interactions on performance is presented.

Evaluation of Flow Field Approximations for Transonic Compressor Stages

1997 ◽  
Vol 119 (3) ◽  
pp. 445-451 ◽  
Author(s):  
D. J. Dorney ◽  
O. P. Sharma
Keyword(s):  
Flow Field ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Loosely Coupled ◽  
Transonic Compressor ◽  
Blade Row ◽  
Flow Through ◽  
And Performance ◽  
Computer Resources ◽  
Fully Coupled

The flow through gas turbine compressors is often characterized by unsteady, transonic, and viscous phenomena. Accurately predicting the behavior of these complex multi-blade-row flows with unsteady rotor–stator interacting Navier–Stokes analyses can require enormous computer resources. In this investigation, several methods for predicting the flow field, losses, and performance quantities associated with axial compressor stages are presented. The methods studied include: (1) the unsteady fully coupled blade row technique, (2) the steady coupled blade row method, (3) the steady single blade row technique, and (4) the loosely coupled blade row method. The analyses have been evaluated in terms of accuracy and efficiency.

Performance of two combine harvester header in soybean crops

2020 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
E. M. Samogim ◽  
T. C. Oliveira ◽  
Z. N. Figueiredo ◽  
J. M. B. Vanini
Keyword(s):  
Experimental Design ◽  
Crop Yield ◽  
Field Performance ◽  
Travel Speed ◽  
The Other ◽  
Combine Data ◽  
Mato Grosso ◽  
Tukey Test ◽  
Combine Harvester ◽  
And Performance

The combine harvest for soybean crops market are currently available two types of combine with header or platform, one of conventional with revolving reel with metal or plastic teeth to cause the cut crop to fall into the auger header and the other called "draper" headers that use a fabric or rubber apron instead of a cross auger, there are few test about performance of this combine header for soybean in Mato Grosso State. The aim of this work was to evaluate the soybean harvesting quantitative losses and performance using two types combine header in four travel speed. The experiment was conducted during soybean crops season 2014/15, the farm Tamboril in the municipality of Pontes e Lacerda, State of Mato Grosso. The was used the experimental design of randomized blocks, evaluating four forward harvesting speeds (4 km h-1, 5 km h-1, 6 km h-1 and 7 km h-1), the natural crops losses were analyzed, loss caused by the combine harvester (combine header, internal mechanisms and total losses) and was also estimated the  field performance of each combine. Data were submitted to analysis of variance by F test and compared of the average by Tukey test at 5% probability. The results show the draper header presents a smaller amount of total loss and in most crop yield when compared with the conventional cross auger.

Growth and Performance of Agriculture Sector in India

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Naresh Singla ◽  
Mamandeep Kaur
Keyword(s):  
Growth Rate ◽  
Capital Formation ◽  
The Other ◽  
Agricultural Credit ◽  
Agricultural Growth ◽  
Indian Economy ◽  
Agriculture Sector ◽  
Food Grain ◽  
And Performance ◽  
Agricultural Labourers

The growth of agriculture and allied sectors is critical for the Indian economy as about 49 percent of the population is directly or indirectly dependent on agriculture. During the last decade and so, the agriculture sector has undergone profound changes resulting in sharp deceleration in its growth. The study has attempted to analyze growth and performance of the agriculture sector in India since 1980-81 and tries to comprehend some of the factors responsible for the deceleration in growth. The study has shown that agriculture sector has been able to show tremendous improvement in expansion of area and production of food grain and non-food grain crops. However, there are so many underlying factors responsible for slowdown of the agricultural growth. Some of the factors identified include: Increase in area under non-agriculture uses, excessive dependence on rain fed farming, increase in number of agricultural labourers, reducing size of the operation holdings, over use of agri-inputs, inequity in the distribution of agriculture credit along with sharp deceleration in public gross capital formation in agriculture etc. The study pointed in order to achieve higher growth rate, there is a need to enhance the gross capital formation in agriculture sector particularly on irrigation so that more area can be brought under assured irrigation. Bringing equity in distribution of agricultural credit coupled with judicious and need-based agricultural inputs are some of the other recommendations drawn based upon the study.

Musical training improves memory for instrumental music, but not vocal music or words

2018 ◽  
Vol 48 (1) ◽  
pp. 150-159
Author(s):  
Jonathan M. P. Wilbiks ◽  
Sean Hutchins
Keyword(s):  
Instrumental Music ◽  
Musical Training ◽  
Vocal Music ◽  
Verbal Material ◽  
The Other ◽  
Musical Experience ◽  
Facilitative Effect ◽  
Musical Excerpts ◽  
And Performance ◽  
The Brain

In previous research, there exists some debate about the effects of musical training on memory for verbal material. The current research examines this relationship, while also considering musical training effects on memory for musical excerpts. Twenty individuals with musical training were tested and their results were compared to 20 age-matched individuals with no musical experience. Musically trained individuals demonstrated a higher level of memory for classical musical excerpts, with no significant differences for popular musical excerpts or for words. These findings are in support of previous research showing that while music and words overlap in terms of their processing in the brain, there is not necessarily a facilitative effect between training in one domain and performance in the other.

The Relation between Angle of Display and Performance in a Prolonged Visual Task

1950 ◽  
Vol 2 (4) ◽  
pp. 176-181 ◽  
Author(s):  
D. C. Fraser
Keyword(s):  
Present Experiment ◽  
Visual Task ◽  
The Other ◽  
Vertical Position ◽  
Display Surface ◽  
Visual Tasks ◽  
And Performance

An experiment is described to test the relation between angle of display and performance in prolonged visual tasks, using the Clock Test in three positions of display surface, vertical, at an angle of 45 degrees to the horizontal, and horizontal. In every case the line of regard was kept at right-angles to the display surface. The results indicate that significantly fewer stimuli are missed in the vertical position of the display surface than in the other two. The deterioration observed in the second half-hour of the original Clock Test experiments was not found in the present experiment, and two possible reasons for this are discussed briefly.

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