Multiple Human Thermal Comfort in a Sedan

Read more about the Human Comfort Module

This sample model demonstrates the use of RadTherm and MuSES to predict transient thermal comfort for multiple humans in realistic environments, in this case, a hot desert environment. This type of analysis provides realistic, localized loading of the air nodes inside the vehicle from both the inert surfaces and the human metabolism. The associated human comfort index allows engineers to test prototype vehicle designs and explore weight and energy-saving innovations.

Each virtual manikin has complete thermoregulatory systems modeled with our Human Comfort Module technology. The simulation begins with several hours of heavy environmental loading from morning until 3:00 PM in the Arizona desert. At 3:00 PM the four passengers enter the vehicle and the AC is switched on high. After 15 minutes, the heat imposed by the AC unit is reduced from -5kw to -4kw. The simulation runs for 30 minutes and human comfort results were exported for each manikin.

An alternative approach to AC simulation can be using the RadTherm and MuSES fluid stream part type with assigned incoming air from a simulated AC condenser.

The results show a high temperature across the manikins after being seated in the vehicle, and the thermal comfort index for each rises to +3 (very uncomfortable). As the AC pulls down the cabin ambient and surface temperatures of the passenger compartment, thermal comfort is restored and, in the case of the front seat occupants, the thermal sensation goes into the slightly cold zone. The vehicle skin temperatures also drop as the interior surfaces are cooled.

Future work for this example model will include adding a CFD analysis to provide higher resolution convection data, based on some assumptions about where the louvers are directing the incoming air.

Our application engineers can provide more information about our services and software technologies covering human comfort, automotive and architectural climate control systems, or general solar energy computations. Contact us to review your application.

Human Comfort Applications

The Multiple Human Comfort Module is useful for determining the comfort of humans in the design of clothing, aircraft, vehicles, and buildings; and can also be applied to address the safety concerns of humans working in thermally significant environments such as firefighters, pilots, foundry workers, and soldiers. The Human Comfort Module operates with Version 9.0 of RadTherm, RadThermIR and MuSES. For certain applications, such as the Federal Aviation Administration certification of aircraft thermal safety for pilots and passengers, the Human Comfort Module has been validated against the ASHRAE two-node model.