An Innovative Development of a Five-Hole Pressure Probe for Highly Unsteady Flow Phenomena

Abstract

An advanced unsteady multi-hole pressure probe is developed in cooperation between the Chair of Aerodynamics and Fluid Mechanics of the Technical University of Munich, the probe manufacturer Vectoflow GmbH and the sensor producer fos4X GmbH. The application of additive manufacturing enables a wide variation in probe geometries. The spatial characteristics of the unsteady probe are determined in the aerodynamic calibration in a known steady uniform jet. Furthermore, the acoustic system inside the channels of the probe is investigated experimentally in the dynamic calibration. Both aerodynamic and dynamic calibration ensure an accurate reconstruction of the velocity components. Measurements of the near wake of a circular cylinder have been recorded with the unsteady probe and compared to data from the literature and corresponding hotwire anemometry measurements. Further improvements to enhance the range of applications of the probe have been initiated: This includes the miniaturization of the probe. Moreover, an unsteady differential fiber-optic sensor and its optic and passive measurement principle are introduced which shall improve the main dynamic specifications of the probe. By combining the additive manufactured pressure probe design and the novel fiber-optic sensor, more accurate measurements of high frequency flow phenomena are expected.

Development of an aerodynamic measurement system for wind turbines

“…In case of the probes, it was necessary to perform an additional calibration after assembling of the probe head and define a calibration matrix for velocities and angles of attack. A detailed description of the calibration process is presented in [13].…”

Aerodynamic probe calibration using Gaussian process regression

“…The interpolation routines can be divided into global or local interpolations, depending on whether all calibration points or only points in the surroundings with similar calibration coefficients should be used. In the local interpolation method, the calibration data is divided into a low-and a highangle regime, see [22]. The pressure port with the highest measured pressure determines the set of calibration coefficients used for reconstruction.…”

Crank-Angle Resolved Flow Measurements in the Intake Duct of a Research Engine Using Novel and Fast Response Aerodynamic Probes

“…The measurement principle is quite simple and is based on gauging the dynamic pressure in both the intake and exhaust duct at the closest possible positions to the valves. To fulfill these requirements aerodynamic probes have been developed and manufactured utilizing 3D printing [ (Heckmeier et al, 2019), (Heckmeier et al, 2020)]. To demonstrate the aforementioned limitation and the potential proposed in the present study, let us choose but not limit ourselves to the precise control of air-fuel ratio (A/F) to the stoichiometric value under certain operating conditions, which is necessary to minimize exhaust emissions in vehicles employing a three-way catalytic converter.…”