The indicated thermal efficiency gives an idea of the
power generated by the engine within the cylinder with
respect to heat supplied in the form of fuel. Figure 7 and
8 represent the effect of brake power on the indicated
thermal efficiency at without and with EGR condition
respectively.The figures show that, with the increase in brake power
the indicated thermal efficiency for each fuel has
increased. Also, with the increase of biodiesel
percentage in blended fuel, the indicated thermal
efficiency gradually decreases. It is due to the lower
calorific value of biodiesel. Form the figures, it is
clearly seen that, with EGR condition, indicated thermal
efficiency increases because of the increase in intake
charge temperature and combustion velocity which is
caused by EGR itself.