Effect of flow dynamics on a rotary wick cooler

This study focuses on design & construction of rotary wick-type evaporative cooler unit, to compare humidification performance under static and dynamic conditions. The humidification process utilizes a wick, that is soaked through both gravity and capillary action. Experiments were conducted by varying the air Reynolds number from 12,223 to 61,114, motor speed from 30 to 90 rpm, and flow rate of water from 0.2 to 0.8 L per minute. The empirical results showed maximum values for temperature drop of 4 °C, specific humidity drop of 1.2 g/kg, coefficient of performance (COP) 5.65, mass transfer coefficient (MTC) 12.54 kg/m²-s, sensible heat ratio (SHR) 0.47, and latent heat ratio (LHR) 0.57. The optimal performance was achieved at a motor speed of 70 rpm and water flow rate (WFR) of 0.6 L per minute (LPM) or 1 × 10⁻⁵ m³/s. When comparing stationary and dynamic wick humidifier units, the dynamic unit demonstrated significantly higher performance with more uniform wettability.