The construction of radiators is one of the more intensively researched areas in the vehicle sector. Available on this subject is a great deal of extensive software literature, experience and measurements with the complete module, and studies concerning the wind behaviour in the engine compartment (wind tunnel). Aerodynamics experts do not like the radiator. They would prefer to hermetically seal off the engine compartment up front. Because this is not at all possible with an internal combustion engine, nowadays the wind resistance in the engine compartment is optimised, by the re-aligning and transforming of components.
Flat tubing-, ribbing-network, synthetic water container
The inside of the radiator is formed by the so-called radiator network. This consists of (flat) tubing and ribbing, (figure 1) which increase the surface area. On the side they join the side plates which are connected to the bottom of the pipes. A long time ago, when the car was developing, much heavier brass was used, which still allowed these radiators to be repaired. Nowadays, the network is made of aluminium and the water tanks on the sides, of reinforced synthetics (polyamide). A gasket is inserted into the connection between the two parts. By border-crimping the aluminium part, a permanent airtight connection is achieved (figure 2).
Soldered or mostly pressed pipe joints
The radiator cannot be completely made out of synthetics, because its ability to transfer heat is too unfavourable. It is, however, possible to produce the network and side plates from die-cast aluminium for the upper-class models (figure 1). In this case, the radiators are, as with aluminium synthetic radiators, still soldered, whereas the lower performance models are joined mechanically by pipe-expansion. The water tanks are sometimes a little larger, thus creating place for additional heat exchangers, (e.g., gearbox oil cooler) of which only the two ends are visible.
Radiators connected in series, warnings
Figure 3 shows the combination of a condenser for the air-conditioning, and the radiator, pooled into one space-saving unit. On the sides are the reservoir and compensation tank for the air-conditioning. Figure 4 shows the set-up in a truck with front-mounted intercooler. The signs in figure 5 show which frost protection is to be used, and warn against direct spraying of the aluminium radiator with high-pressure cleaners. 10/08