Natural plant additive for enhancing the viscosity of lubricant oil.

This study represents to improve the performance of the viscosity of lubricating oil engine behavior against the temperature of the combustion engine oil and to solve problems of facing scientists and industrial purposes like consumption properties of lubricating oil (LO) due to the high temperature inside combustion engine. Extracts natural compounds of frankincense were added to the LO due to frankincense has active physical properties of a heat capacity to a create clear effect on improving the durability of viscosity index was investigated using four general, grades of oil to evaluate viscosity changes against combustion temperature.  Numerical technique was used to evaluate the efficiency of four grades and compare it with the optimum reference sample. The obtained results of efficiency were increased approximately 46.16 %. Derived mathematical model depending on three types of heat transfer like heat transfer convection from solid to LO, heat transfer convection from LO to the frankincense and heat transfer from LO to the liquid phase of frankincense to estimate the change of an oil's viscosity against temperature. As well, proposed mathematical model considers the effect of frankincense on the action of LO with and without frankincense.