Model of the Month: May 2008
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 covering human comfort, automotive and architectural climate control systems, or solar energy computations.
About 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 as a separately-licensed feature within 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. It has also been validated against transient measurements of average skin temperature reported by Stolwijk. Contact us to review your application.
View More Sample Models
This sample model uses thermal design to improve the aircraft’s human comfort while reducing the power load on its climate control system.
This sample demonstrates an evaluation of AC pull-down using two different source air temperature profiles and the resulting effects on localized passenger comfort. The Berkeley Comfort Model provides localized comfort results for each body segment computed from temperatures predicted by our Human Comfort Module.
The analysis for this structure involved a prediction of solar loading as well as air circulation patterns throughout the structure. ThermoAnalytics used RadTherm software to determine the need for transmissive or non transmissive glass and predicted internal temperatures of the Cathedral on a sunny days at both half and maximum occupancy.
A prediction of transient thermal comfort for humans driving a car through the desert. It provides realistic, localized loading of the vehicle's air nodes.
A human thermal model demonstrates the effects of solar intensity and ambient temperature. They drink a cup of coffee as the Human Comfort Module simulates their thermal response to the environment.
RadTherm can predict Formula 1 racetrack surface temperatures. Simulations based on weather and track temperature can be a powerful ally in an event where a racer can win by mere seconds.
We simulated a coil-in-tube cross flow heat exchanger to demonstrate RadTherm's fluid stream and convection heat transfer modeling capabilities. The heat exchanger surfaces were created in Rhino3D and meshed with ANSA. The mesh was exported into RadTherm.
Air travel passengers are all too familiar with the thermal discomforts of summer travel. Our DC-10 model provides insight to thermal management techniques that could improve the experience.
RadTherm can model the thermal behavior of complex systems. In this case, a refrigerated truck transports cargo in a contolled environment. We simulate the vehicle's thermal behavior and the cargo system's thermal response.
One of the most frequent complaints about motorcycles is the engine's heat plume. The plume hits the rider when they're idling in traffic or after getting off the highway. This analysis simulates this heat plume and predicts the temperature increase that the rider will experience.
This sample model demonstrates RadTherm's unique environmental effects applied to architectural analysis. You can generate transient thermal results by combining CFD results with RadTherm.
Thermal simulation of a brake system. The brake model is loosely based on the front rotors of a 2005 Ford Mustang.
This model simulates simple thermostatic control of two heating systems. It represents a common heated plate system used to cure adhesives or control chemical reaction rates.
Modeling the forest canopy generates accurate temperatures or IR signatures of objects in such environments. Studying the canopy can find passive "cool zones" for urban park development. Through simulation, the ideal size and location of trees can be planned to provide improved thermal comfort.
We model the development process of a simple exhaust-shield component model using the supplemental TDFUtility program (supplied with all software from ThermoAnalytics). The TDFUtility is a set of utilities combined into a single executable. We demonstrate how it can improve mesh and model quality.
Sample unmanned ground vehicle signature analysis featuring a simple hybrid drive engine and exhaust system and sensor tower. The defense industry needs to consider the thermal (infrared) signature of its systems under various operating conditions and environments. MuSES performs a full thermal analysis followed by a radiance solution in specific IR wave bands corresponding to the sensor of interest.
The Human Comfort Module is available under a separate license to simulate the thermal response of a human body in an environment with significant thermal loads.
