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The blood flow of human body has much impact on the thermo-physiological response. When person change the posture, the gravity acts changes its direction and thus the blood flow can be changed. It is hypothesized that the gravitational effects of postural changes affect blood flow and skin temperature, which in turn affect comfort. To verify this, in the present study, a subject experiment focusing on postural changes was conducted for two conditions (Case 1 and Case 2). In the Case 1 experiment, the subjects were asked to raise their hands for 10 minutes after 30 minutes of rest in the chair-sitting position. As a result, significant skin temperature change were observed in the upper arm, forearm, and hand. The largest skin temperature change was observed in the hands, which showed a decrease in skin temperature of approximately 1.2 °C. The change had influence on the whole-body average value. In Case 2, the subjects were placed in the supine position for 10 minutes after 30 minutes of rest in the chair position. As a result, a decrease in skin temperature of approximately 1 °C was observed on the hands and 0.5 °C in the foot was observed.

The heating, ventilation, and air-conditioning (HVAC) system in a vehicle is used for both defogging the windshield and ensuring the thermal comfort of passengers. A challenge is that energy savings in the HVAC system lead to decreased system performance. The three objective functions, i.e. defogging performance, thermal comfort, and energy savings, these must be considered in parallel to find the optimized control strategy. In the present study, a transient numerical simulation of the in-vehicle environment is performed and the dependency of performance on the air flow rate and supplied air temperature is analyzed. The criteria of defogging performance and thermal comfort are determined as the constrained conditions. The results show a trade-off relationship between the air flow rate and air temperature in defogging performance and thermal comfort; however, their sensitivities depend on the conditions and the time elapsed. As for transient defogging performance, the air flow rate has greater impact than airflow temperature. The air flow rate and the air temperature are comparable in their effects on equivalent temperature, which is employed as the index of the thermal environment. The blowing condition range that fulfills the criteria makes a transition to a low-energy condition with time elapsed. A control strategy for the air flow rate and temperature is derived considering the transient and steady-state conditions.

As computational fluid dynamics plays a crucial role in vehicle body design, the CFD committee, one of the technical committees comprising JSAE, embarked on a benchmark project in which a number of CFD codes would be tested on the same vehicle body. A wind tunnel test of the 1/5 scale model was conducted to provide reference data for the benchmark test. In this paper, details of the measurements are presented. On the body surface, smooth flow patterns were visualised by tufting. It was also found that total pressure loss in the wake of the model displayed a unique pattern similar to a mushroom cloud. [ABSTRACT FROM AUTHOR]

Butt-welded fine gauge type-K thermocouples of three different diameters, 25, 50 and 100 µm, were produced according to an original method and used for gas and wall temperature measurement in an uncoated substrate so as to compare durability and detection performance. The results showed that 50 µm diameter thermocouples are suitable for this type of measurement, since these thermocouples have a response performance as quick as that of 25 µm thermocouples, and because of excellent toughness. Composition analysis of the produced thermocouples also showed that poor mixture of alumel and chromel was responsible for the weakness of 25 µm thermocouples. [ABSTRACT FROM AUTHOR]

Direct heat loss is defined as heat flowing directly from the combustion gas to the combustion chamber walls. The authors' group has investigated the direct heat loss at combustion chamber walls by means of heat transfer analysis using measured instantaneous wall surface temperature. This study focuses on the cylinder liner of a D.I. diesel engine. The cylinder liner wall receives heat from various objects such as the combustion gas, the piston and the piston rings. Incoming heat from the gas to the wall is separated so that the state of the direct heat loss and the heat loss ratio can be evaluated. As a result, this study shows that the heat loss ratio of the cylinder liner occupies approximately 4% of the heat of supplied fuel and also approximately 20% of the total heat loss through all combustion chamber walls other than the valves. [ABSTRACT FROM AUTHOR]