Numerical Investigation on the Influence of Hot Streak Temperature Ratio in a High-Pressure Stage of Vaneless Counter-Rotating Turbine

Zhao, Qingjun; Wang, Huishe; Zhao, Xiuli; Xu, Jianzhong

doi:10.1155/2007/56097

Cited by 16 publications

(13 citation statements)

References 8 publications

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“…The radial temperature profile used by Qingjun et al (2007) in their simulations shows the same trend, with the expected maximum temperature near the blade's midspan falling to relatively low temperatures near the root and tip in a paraboliclike decay.…”

Section: Inlet Temperature Distributionmentioning

confidence: 68%

“…The inlet profiles used in numerical simulations are usually considerably simplified, as they do not generally incorporate mixing and turbulence factors, but they simply accept that the peak temperatures correspond to the location and configuration of combustor and duct geometry (Qingjun et al (2007)). As the parts of the fluid stream that have a higher temperature, or hot streaks, flow through the transition duct toward the turbine, they are mixed and diffused until they become somewhat less distinct.…”

Section: Inlet Temperature Distributionmentioning

confidence: 99%

“…This is attributed to the lower temperatures near the duct boundaries that are indicated by the previously mentioned radial temperature profile versus a mean uniform profile. Qingjun et al (2007) simulated the operation of a single-stage high-pressure turbine coupled with a vaneless counter-rotating low-pressure turbine. When hot streaks impinged on the leading edge of the vanes, they were drawn over the surfaces of the vanes and into the rotor section.…”

Section: Published Observationsmentioning

confidence: 99%

“…Profiles of total temperature at the inlet of high pressure turbines have been presented by Povey et al (2003) and Qingjun et al (2007) (see Figure 5.2). The relative location of peak total temperature in Figure 5.1 differs from those in previous studies, in which the peak is located close to midspan.…”

Section: Spanwise Profilementioning

confidence: 99%

“…As a constraint in this transformation, we required that the same circumferential average be maintained at each spanwise location. This suggested the application of a sinusoidal modulation to vary the spanwise total temperature profile Figure 5.2: Typical radial profile of turbine inlet total temperature (Qingjun et al, 2007) around the circumference of the inlet.…”

Section: Circumferential Variationmentioning

confidence: 99%

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Effect of Inlet Temperature Non-Uniformity on High-Pressure Turbine Performance

Smith

Chang

Tavoularis

2010

Volume 7: Turbomachinery, Parts A, B, and C

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The temperature of the flow entering a high-pressure turbine stage is inherently non-uniform, as it is produced by several discrete, azimuthally-distributed combustors. In general, however, industrial simulations assume inlet temperature uniformity to simplify the preparation process and reduce computation time In the VI configuration, the hot streaks produced higher time-averaged heat load on the vanes and lower heat load on the blades. As the hot streaks in the VI case passed over the stator vanes, they also spread spanwise due to the actions of the casing passage vortices and the radial pressure gradient; this resulted in a stream entering the rotor with relatively low temperature variations. The hot streaks in the MP case were convected undisturbed past the relatively cool vane section. Relatively high time-averaged enthalpy values were found to occur on the pressure side of the blades in the MP configuration. The non-uniformity of the time-averaged enthalpy on the blade surfaces was lower in the VI configuration. The flow exiting the rotor section was much less non-uniform in the VI case, but differences in calculated efficiency were not significant. i for Claudine and Henri ii

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Section: Inlet Temperature Distributionmentioning

confidence: 68%

Section: Inlet Temperature Distributionmentioning

confidence: 99%

Section: Published Observationsmentioning

confidence: 99%

Section: Spanwise Profilementioning

confidence: 99%

Section: Circumferential Variationmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Inlet Temperature Non-Uniformity on High-Pressure Turbine Performance

Smith

Chang

Tavoularis

2010

Volume 7: Turbomachinery, Parts A, B, and C

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Experimental study of novel passive control methods to improve combustor exit temperature uniformity

2014

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The effect of non-uniform temperature flow which comes in contact with the turbine blades is of paramount importance since the thermal damage that occur to the blade during its operation, is governed by the non-uniformities present in the oncoming flow. This thermal damage leads to increased maintenance cost and reduced life-span of the turbine blades. This paper investigates the effectiveness of some novel passive control techniques to improve the temperature uniformity of the combustor exit flow to address the need to reduce the thermal damage and hence decrease the overall maintenance cost of the gas turbine system. The novel passive control techniques tested in this study include the use of streamlined body or guide vanes in the dilution zone of the combustor. For the guide vanes four different orientations were tested-0°, 30°, 60°, 90°. Extensive experimentation was conducted under different flow conditions. The deviation of the exit temperature from the equilibrium mixing temperature was used to compare the effectiveness of different passive control techniques. It was found that the 30 o guide vanes gave the most uniform temperature flow under majority of cases considered. On an average, the flow with 30 o guide vanes was about 15 % more uniform in temperature as compared to the staggered holes geometry with only 1 % higher pressure loss. The possible reason for this improvement is the combination of swirl and depth to which the dilution flow can enter the dilution zone and mix with the primary hot flow. The streamlined body came second with an improvement in pressure losses. Based on these experimental findings, the use of these guide vanes and streamlined body has potential in the gas turbine industry to deal with the high maintenance cost involved in these systems.

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