Internal combustion engines are very common in our daily lives. Today they range from the cars that most of us drive to the lawn mower that we use to mow the lawn. These engines consume about 30% of the U.S. energy budget, which is about 20% of the world's energy budget. The IC engine that is used in this particular experiment is a four stroke, 1 cylinder engine, with a displacement volume of 77.6ml. The intake and exhaust valves are placed on the side of the cylinder, in a side or flat-head configuration. When air and fuel or gas goes into an IC engine, the output products are; power, exhaust, and heat.

A fan blows air to keep the engine at an acceptable temperature. Forced convection is the process whereby the air receives heat from the alluminum fins casted on the engine head. The rate of heat transfer from the fins to the air can be determined by measuring the flow of cooling air and its temperature rise. In this experiment we will calculate the heat transfer rate from measurements of flow rate and temperature rise in the modified cooling system of the engine.

Q-Dot (Heat Transfer Rate) Calculation:

• Make a data sheet including the following; date/time, room temperature, pressure humidity, exhaust temperature, torque, area, velocity and temperature.
• Insulate the engine with aluminum to capture all the heat coming out of the sides of the engine. Make a funnel so that all captured air will flow out of funnel. (As seen in above photo-IC Engine with cowling)
• Run the engine at speed 1200 and let it warm up
• Start taking data to fill out data sheet. Take data various times.
• After taking data, take the average of all the velocities, and temperatures.
• Now that all data is known, the Q (heat) can be calculated.
• In order to calculate the Q (heat transfer rate), the density (Rho), and mass-flow(M-dot) need to be calculated.
• Since the average temperature is known, use this formula to calculate the density. Rho(Kg/m^3)=(97.6KPa)/((0.287(KJ/Kg*K))*(Average Temperature +273.15)(K))
• Use the density just found, area, and the average velocity to find the M-dot (mass flow). M-dot(Kg/s)=(Rho(Kg/m^3))*(Area(m^2))*(Average Velocity(m/s))
• Use this formula to find Q (Heat); Q (Heat Transfer Rate)(Watts)=(M-dot(Kg/s))*(1.02(KJ/Kg*K))*(46.775(Degree C)).

• Calculate Q (Heat)