Application of Thermal Shear Stress Gauge in Study on Shear Stress Measurement on Underwater Bed Surface

Xu, Hanlin; Xia, Yunfeng; Ma, Binghe; Hao, Si-yu; Zhang, Shi-zhao; Zhe-wei, Cai

doi:10.1016/j.proeng.2015.08.347

Cited by 1 publication

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Flow sensors are extensively used for flow measurements in diverse applications in different fields including aerospace [1,2,3,4,5,6], automotive [7], biomedical [8,9,10,11], environmental [12,13,14,15,16,17], hydrodynamics [18] and the chemical and process industries [19]. They can be broadly classified as either non-thermal or thermal [20].…”

Section: Introductionmentioning

confidence: 99%

“…These have been investigated extensively because of their structural simplicity (no moving parts) and robustness, easy electrical interface, high temporal and spatial resolution, low cost and high reliability when mass fabricated using silicon technology [22,23]. According to their measurement techniques, thermal flow sensors can be segregated into three main types (or configurations): (a) calorimetric flow sensors [3,5,6,15,17,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58], (b) time of flight (TOF) flow sensors [36,59,60,61,62] and (c) hot-wire (HW)/hot-film(HF)flow sensors [4,5,8,9,10,11,13,18,22,23,27,34,36,42,50,63,…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sensitivity Enhancement of Silicon-on-Insulator CMOS MEMS Thermal Hot-Film Flow Sensors by Minimizing Membrane Conductive Heat Losses

Mehmood

Haneef

Ali

et al. 2019

Sensors

View full text Add to dashboard Cite

Minimizing conductive heat losses in Micro-Electro-Mechanical-Systems (MEMS) thermal (hot-film) flow sensors is the key to minimize the sensors’ power consumption and maximize their sensitivity. Through a comprehensive review of literature on MEMS thermal (calorimetric, time of flight, hot-film/hot-film) flow sensors published during the last two decades, we establish that for curtailing conductive heat losses in the sensors, researchers have either used low thermal conductivity substrate materials or, as a more effective solution, created low thermal conductivity membranes under the heaters/hot-films. However, no systematic experimental study exists that investigates the effect of membrane shape, membrane size, heater/hot-film length and M e m b r a n e (size) to H e a t e r (hot-film length) Ratio (MHR) on sensors’ conductive heat losses. Therefore, in this paper we have provided experimental evidence of dependence of conductive heat losses in membrane based MEMS hot-film flow sensors on MHR by using eight MEMS hot-film flow sensors, fabricated in a 1 µm silicon-on-insulator (SOI) CMOS foundry, that are thermally isolated by square and circular membranes. Experimental results demonstrate that: (a) thermal resistance of both square and circular membrane hot-film sensors increases with increasing MHR, and (b) conduction losses in square membrane based hot-film flow sensors are lower than the sensors having circular membrane. The difference (or gain) in thermal resistance of square membrane hot-film flow sensors viz-a-viz the sensors on circular membrane, however, decreases with increasing MHR. At MHR = 2, this difference is 5.2%, which reduces to 3.0% and 2.6% at MHR = 3 and MHR = 4, respectively. The study establishes that for membrane based SOI CMOS MEMS hot-film sensors, the optimum MHR is 3.35 for square membranes and 3.30 for circular membranes, beyond which the gain in sensors’ thermal efficiency (thermal resistance) is not economical due to the associated sharp increase in the sensors’ (membrane) size, which makes sensors more expensive as well as fragile. This paper hence, provides a key guideline to MEMS researchers for designing the square and circular membranes-supported micro-machined thermal (hot-film) flow sensors that are thermally most-efficient, mechanically robust and economically viable.

show abstract