A second generation MEMS surface fence sensor for high resolution wall shear stress measurement

Papen, Tilmann von; Buder, U.; Ngo, Ha-Duong; Obermeier, Ε.

doi:10.1016/j.sna.2004.01.058

Cited by 26 publications

(10 citation statements)

References 8 publications

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“…For avoiding these drawback indirect wall shear stress measurements were developed with various methods. For example, micro-fences using a cantilever structure and piezoresistors are presented in [10]; the exploitation of optical resonances such as whispering gallery modes of dielectric microspheres is proposed in [11] (for which the optical resonance shifts with radial deformations of the spheres due to the shear stress); the deflection of micro-pillars is presented in [12] and thermal-based sensors are presented in the next paragraphs of the present paper. The physical principle used in these latter consists in taking advantage of the convective heat transfer between an electrically heated resistor and a surrounding cooler fluid [6].…”

Section: Figure 1: (A) Schematic Of a Flow Separation On An Airfoil Lmentioning

confidence: 99%

High temperature gradient calorimetric wall shear stress micro-sensor for flow separation detection

Ghouila-Houri

Gallas

Garnier

et al. 2017

Sensors and Actuators A: Physical

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The paper describes and discusses the design and testing of an efficient and high-sensitive calorimetric thermal sensor to measure simultaneously the magnitude and the direction of wall shear stress in aerodynamic flows. The main technical application targeted is the back flow and the flow separation detection for active flow control. The measurement principle is based on the flow-induced forced heat convection transfer on a heater element. The sensor is micro-structured with three parallel substrate-free wires presenting a high aspect ratio and supported by periodic perpendicular SiO2 micro-bridges ensuring a mechanical toughness and a thermal insulation relatively to the bulk substrate with high thermal inertia. The central wire is made of a multilayer structure (Au/TiSiO2/Ni/Pt/Ni/Pt/Ni/SiO2) and is composed of a heater element (Au/Ti) and a thermistor (Ni/Pt/Ni/Pt/Ni) enabling to measure the heater temperature. The upstream and downstream wires are thermistors enabling to operate in the calorimetric mode. This design provides a high temperature gradient and a homogeneous temperature distribution along the wires. The sensor operates in both constant current mode and constant temperature mode, with a feedback on current enabled by uncoupling heating and measure. Welded on a flexible printed circuit, the sensor was flush mounted on the wall of a turbulent boundary layer wind tunnel. The experiments, conducted in both attached and separated flow configurations, demonstrate the sensor sensitivity to the wall shear stress up to 2.4 Pa and the ability of the sensor to perform flow direction sensing for back-flow detection in a separated flow configuration.

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Section: Figure 1: (A) Schematic Of a Flow Separation On An Airfoil Lmentioning

confidence: 99%

High temperature gradient calorimetric wall shear stress micro-sensor for flow separation detection

Ghouila-Houri

Gallas

Garnier

et al. 2017

Sensors and Actuators A: Physical

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“…Often a variety of surface fences or hot-wires (von Papen et al 2004;Ebefors et al 1998;Buder et al 2007) are used as the sensing element in the flow. As well as having the disadvantage of changing the flow, these components are very fragile and susceptible to damage from particles in the flow.…”

Section: State Of the Artmentioning

confidence: 99%

“…The electrical connections were mostly placed downstream. In these cases, the sensor is placed flush within the wall, but the wiring not, as shown in the work of von Papen et al (2004). In this new approach presented here, the integration of the sensors and the necessary subsystems directly into the wall is investigated.…”

Section: State Of the Artmentioning

confidence: 99%

Design and evaluation process of a robust pressure sensor for measurements in boundary layers of liquid fluids

2011

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In this work, the latest results of the design, fabrication and characterization of a new MEMS piezoresistive pressure sensor are presented. Significant changes in the layout as well as in the micro-fabrication process have been made, e.g. anodic bonding of a glass cover on the backside. The sensor has been developed in order to meet the special requirements of measurements in fluid mechanics, particularly with regard to the non-intrusive nature of the sensor. The sensor development, starting with the simulation of mechanical stresses within the diaphragm resulting from a pressure of up to 4 bar is described. These calculations have lead to an optimized placement of the piezoresistors in order to achieve a maximum sensitivity. Important parameters including sensitivity, resonance frequency and maximum load are described precisely. The experiments and the initial results, e.g. its linearity and its dynamic capability are demonstrated.

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“…Often a variety of surface fences [3] or hot-wires [4] are used as the sensing element in the flow. As well as having the disadvantage of changing the flow, these components are very fragile and susceptible to damage from particles in the flow.…”

Section: State Of the Artmentioning

confidence: 99%

“…The electrical connections were mostly placed downstream. In these cases, the sensor is placed flush within the wall, but the wiring not [3]. In this new approach, we integrate the sensors as well the necessary subsystems into the wall.…”

Section: State Of the Artmentioning

confidence: 99%

Robust pressure sensor for measurements in boundary layers of liquid fluids with medium total pressures

et al. 2011

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In this work, the latest results of the design, fabrication and characterization of a new MEMS piezoresistive pressure sensor are presented. It is made of silicon using a boron diffusion process to create piezoresistors. Significant changes in the layout as well as in the micro-fabrication process have been made, e.g. anodic bonding of a Pyrex cover on the backside. These lead to a very precise pressure sensor, which is tailor made for high dynamic measurements in fluids with a total pressure up to 4 bar. This new piezoresistive pressure sensor has been developed in order to meet the special requirements of measurements in fluid mechanics, particularly with regard to the non-intrusive nature of the sensor. The sensor development, starting with the simulation of mechanical stresses within the diaphragm is described. These calculations have lead to an optimized placement of the piezoresistors in order to achieve a maximum sensitivity. The result of this work is a sensor which has well known properties. Important parameters including sensitivity, resonance frequency and maximum load are described precisely. These are necessary to enable new measurements in the boundary layer of fluids. The experiments and the initial results, e.g. its linearity and its dynamic capability are demonstrated in several figures.

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A second generation MEMS surface fence sensor for high resolution wall shear stress measurement

Cited by 26 publications

References 8 publications

High temperature gradient calorimetric wall shear stress micro-sensor for flow separation detection

High temperature gradient calorimetric wall shear stress micro-sensor for flow separation detection

Design and evaluation process of a robust pressure sensor for measurements in boundary layers of liquid fluids

Robust pressure sensor for measurements in boundary layers of liquid fluids with medium total pressures

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