A method for the determination of turbulence intensity by means of a fast response pressure probe and its application in a LP turbine

Lengani, Davide; Paradiso, Berardo; Marn, Andreas

doi:10.1007/s11630-012-0515-8

Cited by 20 publications

(8 citation statements)

References 23 publications

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“…For the determination of the stochastic pressure fluctuations using a FRAPP, the method of Fourier filtering is adopted as previously described by Lengani et al [6,7] and Camp and Shin [8]. The post processing tool for FRAPP data is based on the triple decomposition of the measured value (see Equation 1), which is the total pressure in this case.…”

Section: Determination Of Stochastic Pressure Fluctuationsmentioning

confidence: 99%

Influence of Pressure Fluctuations on the Mean Value of Different Pneumatic Probes

Bauinger

Marn

Göttlich

et al. 2017

IJTPP

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For this study, measurements were carried out in a one-and-a-half stage test turbine. In order to characterize the flow field and to obtain steady flow quantities, five-hole probes are used in the rig in several measurement planes. Although a very high resolution in circumferential and radial direction is possible with five-hole probes, only certain sectors of the flow field can be measured due to quite long measurement times. For this reason, total pressure rakes, which can be traversed 360 degrees in a circumferential direction, were built for this test configuration. During foregoing measurements, differences between the total pressure measured with the rakes and the total pressure measured with a five-hole probes were observed, especially in the measurement plane downstream of the rotor where the flow is highly unsteady. It was found that the measured value for total pressure is particularly influenced by the stochastic pressure fluctuations and turbulence and can therefore deviate significantly from the "real" value.

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Section: Determination Of Stochastic Pressure Fluctuationsmentioning

confidence: 99%

Influence of Pressure Fluctuations on the Mean Value of Different Pneumatic Probes

Bauinger

Marn

Göttlich

et al. 2017

IJTPP

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“…Modal decomposition was used by Lengani et al [19] and more recently by Zerobin et al [20] to decompose the unsteady flow field in temporal and spatial Fourier modes. According to Tyler and Sofrin [21], the pressure fluctuations at any circumferential position downstream of a compressor or turbine stage can be described as the sum of harmonics, represented by a Fourier series.…”

Section: Test Setup and Operating Conditionsmentioning

confidence: 99%

Impact of Turbine-Strut Clocking on the Performance of a Turbine Center Frame

Sterzinger

Merli

Peters³

et al. 2021

Journal of Turbomachinery

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Previous studies have indicated a potential for improving the performance of a Turbine Center Frame (TCF) duct by op- timizing the clocking position between the high-pressure-turbine (HPT) vanes and TCF struts. To assess the impact of clocking on the performance, a new test vehicle with a clockable ratio of HPT vanes to TCF struts, consisting of an HPT stage (aero- dynamically representative of the second-stage HPT engine), a TCF duct with non-turning struts, and a first-stage low-pressure turbine vane, was designed and tested in the transonic test tur- bine facility (TTTF) at Graz University of Technology. This paper quantifies the performance impact of clocking and describes the mechanisms causing TCF flow field changes, lever- aging both experimental and numerical data. Other areas in the TCF duct impacted by the choice of the HPT vane circumfer- ential position including the strength of unsteady HPT-TCF in- teraction modes, TCF strut incidence changes, and carry-over effects to the first LPT vane are additionally highlighted. Five-hole-probe (5HP) area traverses and kielhead-rake tra- verses were used to asses the flow field at the TCF-exit and calcu- late the pressure loss. The flow field at the TCF exit shows signif- icant differences depending on the circumferential position of the HPT vane. A relative performance benefit of 5% was achieved.

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“…The reduced mass flow and speed are referred to 288.15 K and 1013.25 mbar. An example of the other operating points is given in [14]. The tip clearance while in operation has been estimated using measurements of the clearance while not in operation at ambient temperature, in combination with finite element calculations of the blades and rotor-disc as well as the casing, taking into account forces due to the rotation as well as temperature effects.…”

Section: Operating Conditionsmentioning

confidence: 99%

“…With this procedure there are around 11-12 samples per blade passing period (T), as it may be computed from the sampling frequency after "adaptive resampling" (80 kHz) and the shaft rotational speed. From the spectral analysis of the signal (as shown in [14]) it emerged that almost the whole signal energy is included at the blade-passing frequency and its harmonics. Thus the average among the 72 blade passages has been computed.…”

Section: Data Reduction Proceduresmentioning

confidence: 99%

Comparison of a State of the Art and a High Stage Loading Rotor

Selic

Lengani

Schönleitner

et al. 2014

Volume 2C: Turbomachinery

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This paper presents measurement results of a 1½ stage LPT test rig at Graz University of Technology incorporating two different rotor geometries: one with a regular blade loading and a second rotor with a highly loaded blade geometry. The test rig was designed in cooperation with MTU Aero Engines and represents the last 1.5 stages of a commercial aero engine. Considerable efforts were put on the adjustment of all relevant model parameters (Mach number, blade count ratio, airfoil aspect ratio, blade loading, etc.) to reproduce the full scale LPT situation. The rig diameter is approximately half of that of a commercial aero engine LPT. The number of blades and vanes for the two investigated stages as well as the pressure ratio and power output are identical, resulting in a decrease in rotational speed of the HSL rotor. Measurement data from a fast response pressure probe (FRAPP) is used to compare the flow fields of the two different stages.The effect of the different stage designs can be seen when comparing the exit flow fields. The highly loaded stage shows a more pronounced tip leakage vortex compared to the datum stage. The highly loaded stage shows wider wakes with a lower total pressure deficit. The fluctuations of total pressure within the flow field are directly related to the upstream wake. If the measurement position is located within a stator wake, the fluctuations are significantly smaller than out of the wake.

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A method for the determination of turbulence intensity by means of a fast response pressure probe and its application in a LP turbine

Cited by 20 publications

References 23 publications

Influence of Pressure Fluctuations on the Mean Value of Different Pneumatic Probes

Influence of Pressure Fluctuations on the Mean Value of Different Pneumatic Probes

Impact of Turbine-Strut Clocking on the Performance of a Turbine Center Frame

Comparison of a State of the Art and a High Stage Loading Rotor

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