Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Numerical Analysis on the Design of a Thermal Mass Air Flow Sensor with Various Heating Modes

가열모드에 따른 열식 질량유량센서의 설계 해석

  • 전홍규 (서울대학교 기계항공공학부) ;
  • 이준식 (서울대학교 기계항공공학부) ;
  • 박병규 (서울대학교 기계항공공학부)
  • Published : 2007.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

Numerical simulations are conducted for the design of a micro thermal mass air flow sensor (MAFS), which consists of a microfabricated heater and thermopiles on the silicon-nitride ($Si_3N_4$) thin membrane structure. It is important to find the proper locations of these thermal elements in the design of MAFS with improved sensitivity. Three heating modes of the micro-heater are considered: constant temperature, constant power and heating pulses. The analyses are focused on the membrane temperature profile near the sensing section. Considered are the practical flow velocities, ranging from 3 m/s to 35 m/s, and the corresponding Reynolds numbers from 1000 to 10000. The results show that one of optimum sensing locations is about $100{\mu}m$ away from the microheater. It is concluded that the heating mode and configurations of thermal elements are the main factors for the MAFS with higher sensitivity.

Keywords

References

  1. Nguyen, N. T., 1997, 'Micromachined Flow Sensors - A review,' Flow Meas. Instrum., Vol. 8, No. 1, pp. 7-16 https://doi.org/10.1016/S0955-5986(97)00019-8
  2. Ashauer, M., Glosch, H., Hedrich, F., Hey, N., Sandmaier, H. and Lang, W., 1999, 'Thermal Flow Sensor for Liquids and Gases Based on Combinations of Two Principles,' Sensors and Actuators, A 73, pp. 7-13 https://doi.org/10.1016/S0924-4247(98)00248-9
  3. Buchner, R., Sosna, C., Maiwald, M., Benecke W. and LangW., 2006, 'A high-temperature Thermopile Fabrication Process for Thermal Flow Sensors,' Sensors and Actuators, A 130, pp. 262-266 https://doi.org/10.1016/j.sna.2006.02.009
  4. Sparrow, E. M., Goldstein, R. J. and Jonsson, V. K., 1964, 'Thermal Instability in a Horizontal Fluid Layer : Effect of Boundary Conditions and Non-linear Temperature Profile,' J. Fluid Mechanics, Vol. 18, pp. 513-528 https://doi.org/10.1017/S0022112064000386
  5. Sabate, N., Santander, J., Fonseca, L., Gracia, I. and Cane, C., 2004, 'Multi-range Silicon Micromachined Flow Sensor,' Sensors and Actuators, A 110, pp. 282-288 https://doi.org/10.1016/j.sna.2003.10.068
  6. Lammerink, T. S. J., Tas, N. R., Elwenspoek, M. and Fluitman, J. H. J., 1993, 'Micro-Liquid Flow Sensor,' Sensors and Actuators, A 37, pp. 45-50 https://doi.org/10.1016/0924-4247(93)80010-E
  7. Elwenspoek, M., 1999, 'Thermal Flow Micro Sensors,' Proceeding of IEEE Semiconductor Conference, pp. 423-435 https://doi.org/10.1109/SMICND.1999.810580
  8. Madou, M. J., 2002, Fundamentals of Microfabrication, Second Edition, CRC Press
  9. Park, B. K., Lee, J. S. and Oh, D. W., 2006, 'Flow Sensing Devices and Micro Mass Flowmeter with Configurations of Cooling Air Channels,' KR Pat., 10-0692072, G01F 1/69
  10. Qiu, L., Hein, S., Obermeier, E., and Schubert, A., 1996, 'Micro Gas-Flow Sensor with Intergated Heat Sink and Flow Guide,' Sensors and Actuators, A 54, pp. 547-551 https://doi.org/10.1016/S0924-4247(97)80012-X