A Methodology to Measure СP / CV Ratio Using U-shape Acoustic Resonance Tube

The specific heat ratio of gases can be determined using several measuring instruments. Recently acoustic resonance instruments have shown great versatility and are used in various branches of industrial applications. This article proposes a simple measurement methodology to measure the specific heat ratio i.e., Сp / Cv using a free mode of acoustic resonance within a U-shape resonator. The specific heat ratio is calculated by measuring the speed of sound in a tube filled by the sample of the gas under test. For this purpose, the signal of standing wave is acquired using a sound card of Personal Computer. The received signal is rocessed by LabVIEW software. The experimental results show that the measured value of the specific heat ratio of several types of gases can be calculated using the proposed methodology and the relative error is about 2%.