Estimation of the correction term of pitot tube measurements in unsteady (gusty) flows

• The effect of an unsteady flow in Pitot tube measurements have been investigated.
• Based on the potential flow theory, a correction term, Tct have been proposed.
• Influence of the Tct have been investigated with four types of Pitot tubes.
• Influence of the distance between static and total pressure taps xe is investigated.
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• It is mandatory to check the Pitot tubes measurements in a gusty wind tunnel.

In rough environments (train’s underbody, wind carrying sand etc.), the only feasible means of measuring flow speed is with a Pitot tube. Unsteady (gusty) flow effects can cause large errors in flow speed measurements. In this short communication work, an attempt has been made to identify these errors. Based on potential flow theory, a term that takes into account the unsteady effects has been proposed to correct the Pitot tube measurements in unsteady (gusty) flow conditions. Experiments have been performed in an open circuit-closed test-section, low-speed wind tunnel, designed and built at the Instituto de Microgravedad “Ignacio Da Riva” of the Universidad Politécnica de Madrid (IDR/UPM). Different types of Pitot tubes have been used to check the validity of the correction term proposed. It has been shown that the distance between the total and static pressure taps has a major influence on the Pitot tube correction term.