The dynamic characteristics relating to turbulent flow in pipe junctions with roundness at the upstream edge and the upstream and downstream edges of the lateral entrance were solved numerically. The mechanisms of the flow, particularly those of energy loss, were studied in detail.

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Experimental and theoretical studies were made on the heating effects of seasonal ground heat storage of solar energy using a vertical pipe system. This report describes the history of research in the world and the methodology of the study and proposes heat storage and heat recovery systems. A vertical pipe system laid under ground is more suitable for the long-term storage in the cold region in Hokkaido than the horizontal pipe system which has been studied in Europe and the United States. Two heat recovery systems are proposed: natura and mechanical. In the former system, a set of pipes in the soil and a house built on top of them are used together to form the indoor temperature, because of the heat gain from the soil to the house. In the latter system, the heat retained in the soil is forcefully recovered by using a heat pump. The characteristic of the soil temperature variation in Sapporo is calculated and agree with the measured results. The seasonal heat flow from the soil at the surface is also calculated and is about 2.4×10^4kcal/m^2.

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Experimental and theoretical studies were made on seasonal ground storage of solar energy by means of a single vertical pipe. Hot water from a solar collector was injected for 2 months to store heat in the ground and water of about 13℃ was injected to recover the stored heat. The general characteristics of ground heat storage and temperature variations were obtained. Unless insulation was used on the ground over and around the pipe, the majority of the heat stored for a long time escaped due to the climatic characteristics of the cold region. Furthermore, the temperature of the pipe in the heat recovery process had to be as low as possible for heat recovery. At a temperature of 13℃, the heat recovery rate, the ratio of recovered heat to injected heat, was only 3.2%. This was also proven by the results of simulation tests conducted under the same conditions. The effect upon the heat recovery rate when thermal insulation materials were used to prevent heat dissipation was clarified numerically. The max. heat recovery rate, however, was only 17% less than expected. The temperature level of the pipe should be lower to recover heat by using the temperature difference between the pipe and the soil. It is recommended that a large amount of the heat escaping from the ground be taken into the house. In other words, natural heat recovery in which the heat storage and the house are used together to determine the indoor temperature in a natural way.

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Heat loss through the exterior walls of a heated space increases when there exists a partition-wall in the space, due to the additional heat transfer from the partition-wall to the main walls. However, as the mean radiant temperature (MRT) in a space with partition is higher than that without partition, the lower air temperature in such a space may still be acceptable from the viewpoints of thermal comfort. The purpose of this study is to clarify the effects of some environmental as well as architectural parameters on the ratio of heat loss from the aforementioned spaces when analyzing them under the equivalent thermal environment. The space model assumed in this study is the simplest kind, consisting of two parallel, symmetrical and infinite planes-to be called partitioned space if there exists a partition-wall between two planes parallely, and non-partitioned space unless to be so. Moreover, for evaluating the thermal environment a spherical element has been assumed in the space, of which surface-temperature accounts for indicating the thermal environment. In this paper, effects of diverse environmental and architectural parameters will be examined by means of numerical calculation, first of all, on the heat loss ratio of partitioned and non-partitined spaces. Then the critical convective heat transfer coefficient (α_<cg>)_<cr>, that is between the walls and air in the space, will be introduced as an index to grade the energy savings which is due to the existance of partition-wall in the space. When comparing the partitioned and non-partitioned spaces from the energy conservation points of view, there exist two distinguishable zones before and after (α_<cg>)_<cr>. One zone accounts for the values of α_<cg> less than (α_<cg>)_<cr> in which non-partitined space indicates the lesser energy loss. Another zone accounts for the values of α_<cg> greater than (α_<cg>)_<cr> in which the partitioned space shows tendency towards the energy savings- when warming up the space. This (α_<cg>)_<cr>, has found to be proportional to α_<cs>/ε_s where α_<cs> is the convective heat transfer coefficient and ε_s is emissivity of the spherical element, whereas it follows the changes of emissivity of the internal surface of the exterior wall ε_g through a quadratic function which has been approximated by means of numerical calculation. Besides, other than α_<cs>, ε_s and ε_g effects of the other parameters may be summerized as follows. Convective heat transfer coefficient in the vicinity of partition-wall α_<cp>, emissivity of partition-wall ε_p and the overall heat transfer coefficient of the exterior walls have no effect on the value of (α_<cg>)_<cr>, though they certainly impose distinct changes upon the heat loss ratio of partitioned and non-partitioned spaces. However internal heat production and surface-temperature of shperical element as well as ambient temperature not only do not influence the value of (α_<cg>)_<cr> but also have no essential effect on the ratio of heat loss. Nevertheless, it seems necessary to mention here that, although the space models applied in this study differs comparatively from the actual ones, the results concluded in this paper can be reasonably accepted on a qualitative basis. Thus, as a matter of course, they have to be similarly examined on some model analogous to the existing spaces in order to be confirmed quantitatively as well.

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A simple method of predicting a building's seasonal heat load based on only 36 monthly weather averages by using multiple regression analysis is developed. Four multiple regression estimation equations for the heating and cooling of office buildings and residential buildings are verified to be very reliable not only in Japan, but also in such subtropical regions as Taiwan. These equations are liner and consist of only 3 building variables and 2 weather variables, so they can be easily used by any architect to evaluate the design conditions of a building shelter conforming to its climatic context by any without a special knowledge of heat load calculation.

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This paper describes the annual heat load distribution maps in Asia for various buildings. The efficiency of insulation and solar shading in different climatic regions can be observed by using these maps. Furthermore, an optimal method to make building designs more suitable for their climatic context can be developed by using the annual heat load index.

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A pipe fitting is one of the most fundamental pipe joints frequently used in an air duct system and a mechanical piping system. The results of many investigations on the flow in a pipe fitting have already been reported. As a result, excellent experimental formulae for the coefficient of energy loss have been obtained. But, the mechanism of the flow in a pipe fitting does not seem to have been discussed. The authors have made a series of studies on the dividing flow mechanism in a pipe junction and have compared the theoretical results with the experimental results. Both results coincide fairly well. This paper investigates the flow mechanism of the laminar flow in a pipe fitting with a 90° branching angle, a few areal ratios and sharp-edged corners at the lateral entrance, which is one of the most fundamental shapes, in the same manner as those applied to a pipe junction, before investigating its shape with small energy loss. The results are summarized as follows: 1) The flow in a pipe fitting with two-dimensional conduit was analyzed by using the free-streamline theory. 2) The separation point on the wall of the main conduit in the laminar flow was analyzed by the boundary theory. 3) The flow mechanism in a real pipe junction was observed by a flow visualization technique. 4) The analytical results were compared with the experimental results. Both results coincide fairly well.

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