International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 02 | May-2015 www.irjet.net p-ISSN: 2395-0072 © 2015, IRJET.NET- All Rights Reserved Page 1025 Experimental Investigation and Measurement of Contact Angle of Drop on Surface with Triton X-100 as Surfactant in Pure Water Sanjay Mane 1 , Ravindra Yadav 2 , K M Jagdale 3 , T S Gulavane 4 1 Student, Mechanical Engineering Department, Dr. JJMCOE, Jaysingpur, Maharashtra, India 2 Professor, Mechanical Engineering Department, Dr. JJMCOE, Jaysingpur, Maharashtra, India 3 Assistant Professor, Mechanical Engineering Department, AITRC, Vita, Maharashtra, India 4 Assistant Professor, Mechanical Engineering Department, AITRC, Vita, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract- Boiling using surfactant is important in many industrial applications such as the petrochemical processing, pharmaceutical, refining, refrigeration, and food processing, among others. Moreover, surfactants in trace amounts are present in boilers of conventional power plants. The experimental set up for the present investigation includes electric heating wire (D= 0.3 mm and L= 100 mm) submerged in water and mounted horizontally. Two thermocouples and a digital indicator measured the temperature of the heater surface and solution temperature. The actual heat transfer rate is obtained by multiplying the voltmeter and ammeter readings. The main heater also present which heats the solution at 40 0 C to 50 0 C. The camera was fixed to take photos of water drop on nichrome wire for measurement of contact angle. Several different surfactants were available, to check boiling behavior with and without surfactant in water. For this test Triton X-100 (Octylphenol Ethoxylate) was used as surfactant in pure water to reduce the contact angle and increase the heat transfer coefficient. Pool boiling experiments were carried out a relatively wide range of surfactant concentrations Triton X-100 (50 - 200) ppm and heat fluxes (61.53 - 152.79) kw/m 2 . The boiling results show that with the addition of small amounts of surfactants, the saturated nucleate pool boiling heat transfer coefficient of water is found to be altered due to reduction in the surface tension and this enhances the heat transfer. The photographic and visual observations indicate boiling behavior is different than pure water with surfactant and shaped bubbles clustering on the heater surface reducing coalescence. Key Words: Contact angle, wettability, heat transfer, and surface tension 1. INTRODUCTION Nucleate pool boiling phenomenon has attracted considerable research and practical attention , due to its ability to transfer large amounts of heat with relatively small temperature differences. From last 60 years there has been extensive research to address issues such as bubble growth, bubble dynamics, effects of heater surface characteristics, fluid -surface interaction, and fluid properties, among others [1]. In recent years, due to importance that directed towards the energy conservation and economic imperatives, much effort have been made to advance techniques that lead to enhance nucleate boiling heat transfer. The extent of enhancement has been found to be dependent on additive concentrations, its type and chemistry, wall heat flux, and the heater geometry. Many studies, have reported the importance of decreasing the surface tension by adding additives to the solution and its impact on the boiling heat transfer coefficient [5]. 1.1 Contact angle It is defined geometrically as the angle formed by a liquid at the three phase boundary where a liquid, gas and solid intersect. The measurement of a single static contact angle to characterize the interaction is no longer thought to be adequate. For any given solid/ liquid interaction there exists a range of contact angles which may be found. The values of static contact angles are found to depend on the recent history of the interaction. When the drop has recently expanded the angle is said to represent the Ǯadvancedǯ contact angle. When the drop has recently contracted the angle is said to represent the Ǯrecededǯ contact angle. These angles fall within a range with advanced angles approaching a maximum value and receded angles approaching a minimum value. If the three phase (liquid/solid/vapors) boundary is in actual motion the angles produced are called Dynamic Contact Angles and are referred to as Ǯadvancingǯ and Ǯrecedingǯ angles. The difference between Ǯadvancedǯ and Ǯadvancingǯ, Ǯrecededǯ and Ǯrecedingǯ is that in the static case motion is incipient and in the dynamic case motion is actual. Dynamic contact angles may be assayed at various rates of speed. Dynamic contact angles measured at low velocities should be equal to properly measured static angles. In this test static advanced contact angle is measured. The fig. 1 shows the hoe contact angle is formed on surface at three boundary layer.