Dynamic calibration technique for thermal shear-stress sensors with mean flow

Chandrasekaran, V.; Cain, Anthony; Nishida, Toshikazu; Cattafesta, Louis N.; Sheplak, Mark

doi:10.1007/s00348-005-0969-5

Cited by 33 publications

(22 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When measuring fluctuation quantities in high Reynolds number turbulent boundary layers, wall shear stress sensors have to resolve both small length-and velocity-scales at high frequencies, in the view of Kolmogorov scales [4]. Therefore the need of very small, fast and high sensitive measurement devices can be fulfilled by Micro-ElectroMechanical Systems (MEMS) technology [5].…”

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

View full text Add to dashboard Cite

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.

show abstract

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

View full text Add to dashboard Cite

show abstract

“…The sensors were mounted at the bottom of the tube directly below the microphone. Propagating plane waves were expected up to a cutoff frequency of about 34 kHz for this tube [18]. The setup is more completely described in the Materials and Methods Section.…”

Section: Resultsmentioning

confidence: 99%

“…is also indicated, where p is the pressure amplitude, u s is the speed of sound, and ρ air is density of air [18]. The three frequencies shown below are the first resonance frequency.…”

Section: Resultsmentioning

confidence: 99%

High-Bandwidth and Sensitive Air Flow Sensing Based on Resonance Properties of CNT-on-Fiber Hairs

Slinker

Kondash

Dickinson

et al. 2017

View full text Add to dashboard Cite

Abstract:Artificial hair flow sensors were fabricated using piezoresistive, radially grown carbon nanotube arrays on glass fibers and investigated for their dynamic aerodynamic response as measured within an instrumented plane-wave tube. The sensors were experimentally observed to provide both a large bandwidth of operation below first resonance and a strong resonance response at selected frequencies above first resonance. The frequency of first resonance was easily tunable by adjusting the length of the exposed hair and could be made to vary from a few hundred hertz to over 13 kHz. Higher frequency bands were accessible for a given hair length using higher-order resonance modes, up to five of which were observed. All of the responses were understood and modeled using a vibrating Euler-Bernoulli beam analysis.

show abstract

“…The present simulation follows a Womersley velocity profile, in the same way as the analytical expression derived by Chandrasekaran et al [2005] for a squared channel flow in the center-plane. Figure 4 indeed shows a good agreement between simulation, experiment and the analytical solution of Chandrasekaran et al [2005] at the inlet through one flow oscillation cycle.…”

Section: Fluid Simulation Without Flapmentioning

confidence: 95%

The PELskin project—part I: fluid–structure interaction for a row of flexible flaps: a reference study in oscillating channel flow

Favier

Kamps

et al. 2016

Meccanica

View full text Add to dashboard Cite

Previous studies of flexible flaps attached to the aft part of a cylinder have demonstrated a favourable effect on the drag and lift force fluctuation. This observation is thought to be linked to the excitation of travelling waves along the flaps and as a consequence of that, periodic shedding of the von Kármán vortices is altered in phase. A more general case of such interaction is studied herein for a limited row of flaps in an oscillating flow; representative of the cylinder case since the transversal flow in the wake-region shows oscillating character. This reference case is chosen to qualify recently developed numerical methods for the simulation of fluid-structure interaction in the context of the EU funded 'PELskin' project. The simulation of the two-way coupled dynamics of the flexible elements is achieved via a structure model for the flap motion, which was implemented and coupled to two different fluid solvers via the immersed boundary method. The results show the waving behaviour observed at the tips of the flexible elements in interaction with the fluid flow and the formation of vortices in the gaps between the flaps. In addition, formation of vortices upstream of the leading and downstream of the trailing flap is seen, which interact with the formation of the shear-layer on top of the row. This leads to a phase shift in the wave-type motion along the row that resembles the observation in the cylinder case.

show abstract

Dynamic calibration technique for thermal shear-stress sensors with mean flow

Cited by 33 publications

References 26 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

High-Bandwidth and Sensitive Air Flow Sensing Based on Resonance Properties of CNT-on-Fiber Hairs

The PELskin project—part I: fluid–structure interaction for a row of flexible flaps: a reference study in oscillating channel flow

Contact Info

Product

Resources

About