Yoshiichi Ozeki

Evaluation of thermal comfort using combined multi-node thermoregulation (65MN) and radiation models and computational fluid dynamics (CFD)

The 65-node thermoregulation model was developed, based on the Stolwijk model. The model has 16 body segments corresponding to the thermal manikin, each consisting of four layers for core, muscle, fat and skin. The 65th node in the model is the central blood compartment, which exchanges convective heat with all other nodes via the blood flow. Convective and radiant heat transfer coefficients and clothing insulation were derived from the thermal manikin experiments. A thermoregulation model combined with radiation exchange model and computational fluid dynamics (CFD) is proposed. The comprehensive simulation method is described.

Effective radiation area of human body calculated by a numerical simulation

A numerical simulation method is developed for predicting the effective radiation area and the projected area of a human body for any posture. This method is based on the solar heat gain simulation for buildings. To confirm the validity of the present method, predicted effective radiation area factors and projected area factors for both standing and seated persons are compared with those by the measurements. It was found that predicted values agree quite well with those by the subjective experiments within 10% accuracy. The effective radiation area and the diagrams of the projected area factors for a person sitting on the floor are illustrated. Moreover, the angle factors between a standing person and rectangular planes are calculated and compared with the results by Fanger.

Numerical simulation method to predict the thermal environment inside a car cabin

Abstract A numerical simulation, which predicts the thermal environment of a car cabin under varying conditions of car air-conditioning, was developed. The coupled analysis of solar radiation, long-wave radiation, heat conduction through the materials and CFD was used in this method. Using a simplified cabin model, ventilation inside the instrument panel and air leaks from the gaps of interior parts were incorporated. The condition of artificial solar radiation in the laboratory room was also studied. The numerical targets of the simulation accuracy on the thermal environment factors were determined by considering both the experimental error and the range of human perception to the thermal factors experimentally.

Numerical comfort simulator for evaluating thermal environment

Abstract A 65-node thermoregulation model was developed, based on the Stolwijk model. The model has 16 body segments corresponding to a thermal manikin, each consisting of four layers for the core, muscle, fat, and skin. The 65th node in the model is the central blood compartment, which exchanges convective heat with all other nodes via the blood flow. Convective and radiant heat transfer coefficients and clothing insulation were derived from thermal manikin experiments. A thermoregulation model combined with a radiation exchange model and Computational Fluid Dynamics is proposed. The comprehensive simulation method is described.

Effects of spectral properties of glass on thermal comfort of car occupants

Abstract The effect of different sources of radiation on the transmissive and reflective performance of glass was investigated to enable the accurate evaluation of solar radiation through a glass window. The performance of these two properties is quite different with different radiation sources, such as solar radiation from the sun or infrared solar lamps, because of the spectral properties of both the glass and radiation sources. We also discuss how differences in the transmissive and reflective performance of the glass affect the thermal comfort of car occupants. A numerical simulation method, based on comprehensive combined analysis of a thermoregulation model of the human body, radiation models, including thermal radiation and solar radiation, and computational fluid dynamics (CFD) is conducted for this purpose. In addition, the numerical simulation method was combined with a numerical thermal manikin model, including the algorithm for the control system of the thermal manikin, and tested for its effectiveness for the evaluation of thermal comfort. It was shown that the numerical model performed equally well and therefore could be used as a substitute for the thermal manikin for the assessment of equivalent temperature in the experiments discussed in ISO/NP-14505.

EFFECTS OF THE SOLAR REDUCTION GLASS ON THE CAR OCCUPANT'S THERMAL COMFORT BY A NUMERICAL SIMULATION

Thermal comfort for car occupants is important factor for automotive design. We have been developing efficient solar reduction glass for vehicles. We also developed a numerical simulator to predict and evaluate the thermal environment and thermal comfort in vehicles. In this simulation, firstly distribution of solar radiation energy through the glass can be calculated actually, and then temperature and air flow distribution, and human comfort can be computed by a combined analysis of CFD (computational fluid dynamics), thermal radiation and body temperature control model which corresponds to shapes of a vehicle and human body. The thermal environment differences between solar reduction glass and normal glass should be clear, which makes the effects of functional glass clear from the view point of human comfort. It is possible to calculate comprehensive situations and indices of thermal comfort evaluation. Using this simulator, it was confirmed quantitatively that Asahi Glasss solar reduction glass could reduce the air-conditioning power than normal glass in summer condition. Furthermore, it was confirmed quantitatively that our functional glass could supply more comfortable environment for passengers inside car occupants. This result shows the latest value of automotive glass depending on human feelings. (A) For the covering abstract see ITRD E121867.