# Reynolds Number Effects on the Non-Nulling Calibration of a Cone-Type Five-Hole Probe for Turbomachinery Applications

• Lee, Sang-Woo (School of Mechanical Engineering, Kumoh National Institute of Technology) ;
• Jun, Sang-Bae (School of Mechanical Engineering, Kumoh National Institute of Technology)
• Published : 2005.08.01

#### Abstract

The effects of Reynolds number on the non-nulling calibration of a typical cone-type five-hole probe have been investigated for the representative Reynolds numbers in turbomachinery. The pitch and yaw angles are changed from - 35 degrees to 35 degrees with an angle interval of 5 degrees at six probe Reynolds numbers in range between $6.60{\times}10^3\;and\;3.17{\times}10^4$. The result shows that not only each calibration coefficient itself but also its Reynolds number dependency is affected significantly by the pitch and yaw angles. The Reynolds-number effects on the pitch- and yaw-angle coefficients are noticeable when the absolute values of the pitch and yaw angles are smaller than 20 degrees. The static-pressure coefficient is sensitive to the Reynolds number nearly all over the pitch- and yaw-angle range. The Reynolds-number effect on the total-pressure coefficient is found remarkable when the absolute values of the pitch and yaw angles are larger than 20 degrees. Through a typical non-nulling reduction procedure, actual reduced values of the pitch and yaw angles, static and total pressures, and velocity magnitude at each Reynolds number are obtained by employing the calibration coefficients at the highest Reynolds number ($Re=3.17{\times}10^4$) as input reference calibration data. As a result, it is found that each reduced value has its own unique trend depending on the pitch and yaw angles. Its general tendency is related closely to the variation of the corresponding calibration coefficient with the Reynolds number. Among the reduced values, the reduced total pressure suffers the most considerable deviation from the measured one and its dependency upon the pitch and yaw angles is most noticeable. In this study, the root-mean-square data as well as the upper and lower bounds of the reduced values are reported as a function of the Reynolds number. These data would be very useful in the estimation of the Reynolds-number effects on the non-nulling calibration.

#### References

1. Abernethy, R. B., Benedict, R. P. and Dowdell, R. B., 1985, 'ASME Measurement Uncertainty,' ASME Journal of Fluids Engineering, Vol. 107, pp. 161-164 https://doi.org/10.1115/1.3242450
2. Anderson, J. D., Jr., 1990, Modern Compressible Flow with Historical Perspective, Series in Aeronautical and Aerospace Engineering, McGraw-Hill, p. 6
3. Coldrick, S., Ivey, P. and Wells, R., 2002, 'Considerations for Using 3D Pneumatic Probes in High Speed Axial Compressor,' ASME Paper No. GT-2002-30045
4. Dominy, R. G. and Hodson, H. P., 1993, 'An Investigation of Factors Influencing the Calibration of Five-Hole Probes for Three-Dimensional Flow Measurement,' ASME Journal of Turbomachinery, Vol. 115, pp. 513-519 https://doi.org/10.1115/1.2929281
5. Hoffmann, G. D., Rabe, D. C. and Poti, N. D., 1980, 'Flow Direction Probes from a Theoretical and Experimental Point of View,' Journal of Physics E-Scientific Instruments, Vol. 13, pp.751-760 https://doi.org/10.1088/0022-3735/13/7/014
6. Koschel, W. and Pretzsch, P., 1988, 'Development and Investigation of Cone-Type Five-Hole Probes for Small Gas Turbine,' Proceedings Of 9th Symposium on Measuring Techniques in Transonic and Supersonic Flows in Cascade and Turbomachines, Oxford, United Kingdom
7. Lee, S. W., Lee, J. S. and Ro, S. T., 1994, 'Experimental Study on the Flow Characteristics of Streamwise Inclined Jets in Crossflow on Flat Plate,' ASME Journal of Turbomachinery, Vol. 116, pp.97-105 https://doi.org/10.1115/1.2928283
8. Lee, S. W., Kim, Y. B. and Lee, J. S., 1997, 'Flow Characteristics and Aerodynamic Losses of Film-Cooling Jets with Compound Angle Orientations,' ASME Journal of Turbomachinery, Vol. 119, pp.310-319 https://doi.org/10.1115/1.2841114
9. Lee, S. W., Park, S. W. and Lee, J. S., 2001a, 'Flow Characteristics Inside Circular Injection Holes Normally Oriented to a Crossflow: Part I - Flow Visualizations and Flow Data in the Symmetry Plane,' ASME Journal of Turbomachinery, Vol. 123, pp. 266-273 https://doi.org/10.1115/1.1344876
10. Lee, S. W., Joo, S. K. and Lee, J. S., 2001b, 'Flow Characteristics Inside Circular Injection Holes Normally Oriented to a Crossflow: Part II-Three-Dimensional Flow Data and Aerodynamic Loss,' ASME Journal of Turbomachinery, Vol. 123, pp.274-280 https://doi.org/10.1115/1.1348016
11. Lee, S. W. and Yoon, T. J., 1999, 'An Investigation of Wall-Proximity Effect Using a Typical Large-Scale Five-Hole Probe,' KSME International Journal, Vol. 13, pp.273-285
12. Ligrani, P. M., Singer, B. A. and Baun, L. R., 1989, 'Spatial Resolution and Downwash Velocity Corrections for Multiple-Hole Pressure Probe in Complex Flow,' Experiments in Fluids, Vol. 7, pp.424-426 https://doi.org/10.1007/BF00193427
13. Prenter, P. M., 1975, Splines and Variational Methods, Wiley-Intersciences
14. Sitaram, N., Lakshminarayana, B. and Ravindranath, A., 1981, 'Conventional Probes for the Relative Flow Measurement in a Turbomachinery Rotor Blade Passage,' ASME Journal of Turbomachinery, Vol. 103, pp.406-414
15. Smith, A. L. and Adcock, J. B., 1986, 'Effect of Reynolds Number and Mach Number on Flow Angularity Probe Sensitivity,' NASA TM-87750
16. Treaster, A. L. and Yocum, A. M., 1979, 'The Calibration and Application of Five-Hole Probes,' ISA Transactions, Vol. 18, pp. 23-34