Typical Performance Characteristics of Gas Turbine Radial Compressors

1964 ◽  
Vol 86 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Colin Rodgers
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Area Ratio ◽  
Diameter Ratio ◽  
Performance Characteristics ◽  
Blade Angle ◽  
Typical Performance ◽  
Compressor Surge

If the peak impeller and diffuser efficiencies are prescribed, it is found that the characteristics of high-speed radial compressors with straight radial blades are basically functions of the inducer and diffuser throat areas. Estimated characteristics for twenty-seven compressor geometries are presented to indicate the effects of inducer blade angle, diffuser throat to impeller inlet area ratio, and impeller tip to inducer RMS diameter ratio. The probable location of compressor surge as influenced by inducer and diffuser blade stalling is discussed, and comparisons of estimated and test compressor characteristics are given.

Compressor Instability Analysis Within a Hybrid System Subject to Cycle Uncertainties

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Alessandra Cuneo ◽  
Alberto Traverso ◽  
Aristide F. Massardo
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Stochastic Analysis ◽  
High Speed ◽  
Operating Conditions ◽  
Operational Parameters ◽  
Surge Margin ◽  
Speed Range ◽  
Compressor Surge

The dynamic modeling of energy systems can be used for different purposes, obtaining important information both for the design phase and control system strategies, increasing the confidence during experimental phase. Such analysis in dynamic conditions is generally performed considering fixed values for both geometrical and operational parameters such as volumes, orifices, but also initial temperatures, pressure. However, such characteristics are often subject to uncertainty, either because they are not known accurately or because they may depend on the operating conditions at the beginning of the relevant transient. With focus on a gas turbine fuel cell hybrid system (HS), compressor surge may or may not occur during transients, depending on the aforementioned cycle characteristics; hence, compressor surge events are affected by uncertainty. In this paper, a stochastic analysis was performed taking into account an emergency shut-down (ESD) in a fuel cell gas turbine HS, modeled with TRANSEO, a deterministic tool for the dynamic simulations. The aim of the paper is to identify the main parameters that impact on compressor surge margin. The stochastic analysis was performed through the response sensitivity analysis (RSA) method, a sensitivity-based approximation approach that overcomes the computational burden of sampling methods. The results show that the minimum surge margin occurs in two different ranges of rotational speed: a high-speed range and a low-speed range. The temperature and geometrical characteristics of the pressure vessel, where the fuel cell is installed, are the two main parameters that affect the surge margin during an emergency shut down.

A New Device for Increasing Output of Marine Current Energy

2013 ◽  
Vol 291-294 ◽  
pp. 1989-1992
Author(s):  
Zhi Yong Dong ◽  
Xu Zhang ◽  
Li Wang ◽  
Bin Shi
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
Area Ratio ◽  
Diameter Ratio ◽  
Stream Velocity ◽  
New Device ◽  
University Of Technology ◽  
Marine Current Turbine ◽  
Marine Current ◽  
Current Energy

In this paper, a speeding-up inlet was developed to increase the free stream velocity in the marine current in order to increase the input energy of turbine. This study was conducted in the Hydrodynamics Laboratory at Zhejiang University of Technology. By using high-speed camera, acoustic Doppler velocimetry (ADV), the influence of area ratio and length-diameter ratio on rotational speed of the turbine was experimentally investigated. Experimental results showed that both area ratio and length-diameter ratio have significant influences on the rotational speed of marine current turbine.

Performance Characteristics of Spiral-Groove and Shrouded Rayleigh Step Profiles for High-Speed Noncontacting Gas Seals

1969 ◽  
Vol 91 (1) ◽  
pp. 60-68 ◽  
Author(s):  
H. S. Cheng ◽  
V. Castelli ◽  
C. Y. Chow
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Performance Characteristics ◽  
Spiral Groove ◽  
Typical Performance ◽  
The Difference ◽  
Gas Seals ◽  
Groove Seal ◽  
Film Characteristics ◽  
Film Profile

Current methods in gas lubrication have been used in this paper to analyze the gas-film characteristics in a high-speed, face-type gas seal. Detailed analyses are presented for two different surface geometries, the spiral-groove-orifice seal and the shrouded Rayleigh step seal. Results are presented in three parts. The first part shows the performance of a spiral-groove seal without the orifices, and also the difference in performance when the grooves are located at the high pressure, low pressure, or both sides. The second part gives typical performance of a nonparallel film profile for the spiral-groove-orifice seal as well as for the shrouded Rayleigh step seal. In the last part, a comparison is made between the two seal geometries on their tolerance to coning or dishing under a constant seal load.

scholarly journals Wall Temperature Measurements in Gas Turbine Combustors With Thermographic Phosphors

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Patrick Nau ◽  
Zhiyao Yin ◽  
Oliver Lammel ◽  
Wolfgang Meier
Keyword(s):  
Gas Turbine ◽  
Wall Temperature ◽  
Gas Turbines ◽  
High Speed ◽  
Bluff Body ◽  
Temperature Measurements ◽  
Transient Temperature ◽  
High Time Resolution ◽  
Ceramic Surface ◽  
Precessing Vortex Core

Phosphor thermometry has been developed for wall temperature measurements in gas turbines and gas turbine model combustors. An array of phosphors has been examined in detail for spatially and temporally resolved surface temperature measurements. Two examples are provided, one at high pressure (8 bar) and high temperature and one at atmospheric pressure with high time resolution. To study the feasibility of this technique for full-scale gas turbine applications, a high momentum confined jet combustor at 8 bar was used. Successful measurements up to 1700 K on a ceramic surface are shown with good accuracy. In the same combustor, temperatures on the combustor quartz walls were measured, which can be used as boundary conditions for numerical simulations. An atmospheric swirl-stabilized flame was used to study transient temperature changes on the bluff body. For this purpose, a high-speed setup (1 kHz) was used to measure the wall temperatures at an operating condition where the flame switches between being attached (M-flame) and being lifted (V-flame) (bistable). The influence of a precessing vortex core (PVC) present during M-flame periods is identified on the bluff body tip, but not at positions further inside the nozzle.

Effect of the turning angle on the flow and performance characteristics of long S-shaped circular diffusers

2003 ◽  
Vol 217 (1) ◽  
pp. 29-41 ◽  
Author(s):  
R B Anand ◽  
L Rai ◽  
S N Singh
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Area Ratio ◽  
Secondary Flows ◽  
Performance Characteristics ◽  
Pressure Recovery ◽  
Recovery Coefficient ◽  
Turning Angle ◽  
And Performance ◽  
Pressure Recovery Coefficient

The effect of the turning angle on the flow and performance characteristics of long S-shaped circular diffusers (length-inlet diameter ratio, L/Di = 11:4) having an area ratio of 1.9 and centre-line length of 600 mm has been established. The experiments are carried out for three S-shaped circular diffusers having angles of turn of 15°/15°, 22.5°/22.5° and 30°/30°. Velocity, static pressure and total pressure distributions at different planes along the length of the diffusers are measured using a five-hole impact probe. The turbulence intensity distribution at the same planes is also measured using a normal hot-wire probe. The static pressure recovery coefficients for 15°/15°, 22.5°/22.5° and 30°/30° diffusers are evaluated as 0.45, 0.40 and 0.35 respectively, whereas the ideal static pressure recovery coefficient is 0.72. The low performance is attributed to the generation of secondary flows due to geometrical curvature and additional losses as a result of the high surface roughness (~0.5 mm) of the diffusers. The pressure recovery coefficient of these circular test diffusers is comparatively lower than that of an S-shaped rectangular diffuser of nearly the same area ratio, even with a larger turning angle (90°/90°), i.e. 0.53. The total pressure loss coefficient for all the diffusers is nearly the same and seems to be independent of the angle of turn. The flow distribution is more uniform at the exit for the higher angle of turn diffusers.

High speed centrifugal compressor surge initiation characterization

1996 ◽  
Author(s):  
William Oakes ◽  
Patrick Lawless ◽  
John Fagan ◽  
Sanford Fleeter
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Compressor Surge

Position sensorless starting of super high-speed PM Generator for micro gas turbine

2006 ◽  
Vol 53 (2) ◽  
pp. 415-420 ◽  
Author(s):  
M. Morimoto ◽  
K. Aiba ◽  
T. Sakurai ◽  
A. Hoshino ◽  
M. Fujiwara
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Micro Gas Turbine ◽  
Position Sensorless
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