Amalgamation of stress wave force balance with artificial intelligence: An alternative way of drag force measurement in supersonic flows

Abstract

The present investigation demonstrates the efficacy of strain gauge and piezofilm as a potential force measurement sensor and Adaptive Neuro Fuzzy Inference System (ANFIS) as a drag force prediction strategy in an impulse test facility. A stress-wave force balance (SWFB) system incorporated with a hemispherical model was intended to measure simultaneous strain histories during shock tube-based tests. Moreover, owing to the high blockage factor during actual experiments, almost unsteady drag force is expected; thereby, dynamic calibration experiments were also performed with impulse hammer. These calibration experiments aimed to estimate the system response function for de-convolution technique and obtain optimal network parameters in the case of the artificial intelligence architecture. Subsequently, the acquired responses at 125 kHz during dynamic calibration tests and shock tube experiments are analyzed in temporal as well as in frequency domain to assess the behavior of these sensors in a short duration environment. Afterward, using the experimentally acquired strain responses, the drag force acting on the model during the experiment was estimated through the usage of de-convolution algorithm and ANFIS. An in-house solver was also used to perform the numerical simulations to predict the temporal variation of the drag force. Encouraging agreement within the uncertainty band of ± 10% was perceived during the comparative assessment of the drag force. The numerical prediction and the drag force magnitude recovered from the piezofilm and the strain gauge response were estimated to be 334 N, 354 N, and 362 N, respectively. The findings designated piezofilm as a potential sensor for short-duration force measurements. Moreover, comparative assessment of the findings of ANFIS and de-convolution technique also turned out to be an encouraging exercise, as the ability of ANFIS to predict short-duration forces was established.