The overall objective of this senior project is to develop, via testing and analysis, a guided process that will aid the Cal Poly Formula SAE team in designing their cooling system. More specifically, a set of designed tests will yield the results necessary in determining a combination of fan and radiator that will achieve appropriate cooling.
A test section that has the capability of interfacing with both the wind tunnel in the Thermal Science Lab and a radiator will be used to facilitate the necessary experiments. The wind tunnel is powered by fan controlled by a variable frequency drive that can induce a range of air flow rates through the duct and radiator. Five tests will be performed, whose goals are as follows:
- Determine mass flow rate of the cooling water as a function of the crank shaft rotational speed.
- Determine heat rejected from the engine to the cooling water as a function of crank shaft rotational speed.
- Determine the mass flow rate of air through the core as a function of car speed.
- Determine static pressure drop of the air across the radiator core at varying air mass flow rates.
- Determine the heat rejection rate associated with a test radiator as a function of both the mass flow rate of air through the core and the mass flow rate of cooling water.
These tests will develop relationships that will ultimately allow the formula team to predict the heat rejection necessary at every car speed as well as the ability of a particular radiator to reject heat at those speeds.
A guided process will be presented that will aid the team in designing the cooling system to be used on the formula competition car. By performing these tests, the FSAE team can choose an appropriate radiator type and face area for the racecar’s specific cooling needs each year. This process will allow the team to minimize the radiator’s size and optimize cooling to increase performance.
The following report will detail background information regarding a car’s cooling system, a description of conceptual designs, the final design process, the test procedures and finally sample results produced via testing.
Source: California Polytechnic State University
Authors: Lisa Van Den Berg | Brandon Lofaro