A Coaxial Cylinder Type Rotational Viscometer- Design and Optimization
نویسندگان
چکیده
The history of viscosity measurements is outspread and is believed to date back to when people began measuring the viscosities of engine oils with the advent of the automobile industry [1]. A rotational viscometer is one which can be used to measure viscosity at different temperature. In this treatise, a coaxial cylinder type rotational viscometer (CCTRV) has been designed, constructed and compared with existing one in order to obtain more accurate data of viscosity of any liquid.Actually, a CCTRV is such a type in which a solid (inner) cylinder is rotated inside a hollow cylinder which contains test sample of liquid. The torque experienced by the solid cylinder due to viscous effect of the test sample is measured and hence viscosity can be calculated.The temperature of the sample is maintained by a temperature controlling bath (TCB).The materials need to fabricate this CCTRV were locally available what results a minimization of cost to obtain it. It has been tried to design and construct it with low cost. However, end effecs is a difficulty when design of a CCTRV is taking place. Many scientist developed empirical equation for compensating it. But in the present design, it was escheweddue to having insignificant gaps in the bottom of the CCTRV. Finally, absolute viscosity of different liquid has been measured with the constructed viscometer and made a comparison with a saybolt viscometer and a correction coefficient has been provided.
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