Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Uludağ Üniversitesi, Turkey
Approval Date: 2008
Thesis Language: Turkish
Student: ŞEMSETTİN MELİH AKYOL
Supervisor: MUHSİN KILIÇ
Abstract:Parameters affecting the thermal comfort are; air temperature, relative humidity, mean radiant temperature and air velocities on human body segments. At this study, the effects of nonuniform and highly transient thermal comfort parameters on physiological reactions and thermal sensation of a driver during the heating and cooling periods in an automobile were investigated both experimentally and theoretically. Experiments were performed both summer and winter conditions. In order to determined temperature distribution in automobile, data were taken from knee and head levels of four seats. In addition to that, temperatures and velocities around the human body segments were measured at 11 and 17 different points respectively. Relative humidity and measurements were performed from the head region of the driver. To obtain mean radiant temperature, globe thermometer was placed 0.6 m height from the floor level and the data were taken from globe thermometer were corrected with air temperature and velocity measurements around the globe thermometer. Two different ventilation modes (instrumental panel vents, foot and windshield vents) and three velocity step of HVAC system were tested in the experiments.Theoretical studies were executed as two steps. In the first step, dynamic and close loop Matlab-Simulink model of the human body was developed to simulate thermal interactions between the driver and environment, driver body temperatures and behaviour of the thermoregulatory control mechanism. In the simulation, the human body separated to 16 body segments to predict local dissatisfactions.In the second step, thermal behaviour simulation of the passenger compartment was prepared to benefit from thermodynamic's basic laws. With the model interior air temperature and mean radiant temperature can be calculated for different states of sun radiation, car speed, and ambient temperature. The effects of optical and thermophysical properties of the compartment metarials to interior thermal conditions and driver thermal comfort were investigated. Experimental studies revealed that for the same conditions foot and windshield vents mode was more efficient to obtain homogeneous temperature distribution on the driver during the heating periods. For panel vents mode high air velocities affect driver body segments especially arms and hands owing to exposed vent air directly. This couses considerable temperature decline and low thermal sensations at skin surfaces.Simulation results were conclused that cooling loads, can be reduced after a vehicle parked inthe sun with increasing insulation thickness and using solar reflective glass and paint.