Performance Analysis of Partially Blocked Car Radiator

Effective heat transfer through the radiator is essential not only for maintaining optimal engine performance but also for extending the lifespan of engine components. However, a decline in the efficiency of the radiator can occur over time due to fouling onto the walls of the radiator tubes. The accumulation of these deposits leads to partial blockages, which negatively affect the radiator’s performance. In this paper, the design and simulation of Maruti 800 standard radiator are conducted to investigate the key parameters that influence radiator performance. Liquid water is used as the engine coolant, flowing through the tubes, while air flows on the outside to cool the heated water. The thermal performance of the radiator is calculated analytically using the effectiveness-NTU (ε-NTU) method to determine the outlet temperatures for both the waterside and air-side flows. Additionally, the radiator design is simulated using computational fluid dynamics (CFD), specifically with ANSYS Fluent 16.0 software. The results obtained from the CFD simulations are compared with theoretical results to validate the accuracy of the CFD method. The effect of blockages is then examined over a range of mass flow rates, from 30 to 100 kph. This analysis considers blockages caused by fouling, simulating real-world degradation that restricts coolant flow and reduces thermal performance. Various levels of blockages, ranging from 25% to 75% due to fouling, are investigated to determine the water outlet temperatures under different conditions. In addition to these blockage levels, a worst-case scenario is modeled to understand the conditions under which the radiator would lose effectiveness entirely. This extreme scenario helps define critical thresholds for maintenance, highlighting the level of fouling at which the radiator can no longer provide adequate cooling. By modeling the rate of accumulation and fouling in the radiator, the time required for complete blockage has been estimated, after which the radiator would become ineffective. The results indicate that the recommended interval for flushing a radiator is every 30,000 miles. Further studies should be conducted with anti-freeze coolants to investigate the optimal flushing period.