In urban region the surface of the earth is rough due to various buildings. It is well known that surface roughness increases the absorptivity of the material for radiation. The purpose of this study is to know the absorption of the solar radiation by the surface on which there are various buildings. In this paper, the absorption of the solar radiation by open two-dimensional rectangular cavity which is the simplest configuration of the surface roughness is calculated. In the calculation it is assumed that each surface composing the cavity is gray and diffusely reflecting surface whose absorptivity for radiation is constant a_e. The ratio of the height H to the width B of the cavity and the absorptivity a_e of the surface are changed as parameters. The extents of these parameters are as follows, H/B is changed between 0 and 3, and a_e is changed between 0.3 and 0.8. The solar radiation is divided into the sky radiation and the direct solar radiation. Therefore the absorptivity of the cavity for each radiation is calculated respectively. (1) Absorptivity for sky radiation For the sky radiation the absorptivity a_c of the cavity is calculated and is shown in a graphic form. The absorptivity a_c increases in a monotone as H/B increases. But the increment of the absorptivity, a_c-a_e, by interreflection among the surfaces composing the cavity takes the maximum value at a certain a_e (=a_<em>). The maximum increment and a_<em> are shown as a function of H/B. Moreover the mean absorptivity a_s of the surface in which open two-dimensional rectangular cavities are arranged regurally at constant pitch are calculated. The value of a_s takes the maximum value when the cavities are arranged at a certain pitch which is determined by H/B and a_e. (2) Absorptivity for direct solar radiation For the direct solar radiation the absorptivity of the cavity is influenced by the injection angle ψ of the radiation which is defined as an angle between the radiation and the horizontal plane. In this case the values of a_c, a_c-a_e and a_s are shown at the various injection angles. The absorptivity a_c takes the maximum value at a certain injection angle ψ_m. The angle ψ_m is 90 degrees when H/B is large, but ψ_m is tan^<-1> (H/B) when H/B is small. The injection angle of the direct solar radiation changes with time from sunrize to sunset. The mean absorptivity throughout whole day considering the change of the injection angle is calculated. This absorptivity changes with a direction of the cavity and the time of the year. Therefore the mean absorptiviy of the cavity at the representative days of the year, namely at the vernal equinox, the summer solstice, the autumnal equinox and the winter solstice, is calculated. It is shown that the absorptivity of the cavity which lies east and west changes greatly with season.

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Simulation studies for 124 cases in which values for elements were varied were conducted by the use of the math models described in Part 1. In this report, the study results are presented in an arranged form, and consideration for energy saving effects, solar heat dependent factor and design optimization are described.

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Large quantities of warm water discharges from steam electric power plants and various factories raise the temperatures of natural bodies of water. Aquatic organisms are affected directly by temperature increases but, in addition, they are affected indirectly through temperature effects on other forms of aquatic life which compriese their food, competitors, and predators. Furthermore, temperature increases diminish dissolved oxygen and make the sensitivity of aquatic life greater to toxic materials. Firstly, it is important to study how the warm water discharge disperses into a natural body of water, if we want to clarify undesirable temperature effects on aquatic life. The purpose of this study is to clarify the factors which influence the dispersion of warm water jets into a river or a channel and to investigate their qualitative influences on the dispersion of warm water. It is desirable to investigate the influences of all factors which appear in the dispersion problems of warm water in a natural river or a channel, but it is very difficult due to various restrictions. In this study attention will be limited to the influences of some important factors to be examined by using simplified rectangular open channels. In this paper, as the first step, the dimensionless groups which influenced the dispersion of warm water were clarified for the steady flow in case that warm water was discharged horizontaly into a rectangular open channel. The dimensionless groups which governed the dispersion of warm water were derived by rewriting the equations of continuity, momentum and energy, and the boundary conditions to dimensionless forms under several reasonable assumptions. They are Reynolds number (Re=U_mR/H), Froude number (Fr=U_m/√<gH>), densimetric Froude number (F_0=U_m/√<(ρ_c-ρ_h)gH/ρ_c)>, velocity ratio (u_m/U_m), heat loss from water surface (q_s^*), and five geometrical boundaries of the channel (W/H, B/H, C/H, D/H, l/H), where U_m=mean velocity in open channel,R=hydrauric mean depth, ν=kinematic viscosity, g=acceleration of gravity, H=depth of channel, ρ_c, ρ_h=densities of fluid at temperature of cold waterbody T_c and temperature of warm water T_h respectively, u_m=mean discharge velocity, W=width of channel, B, C, D=dimensions and depth of discharge channel and l=roughness of channel wall. Similar experiments were undertaken for four typical flows to make sure if the dispersion of warm water can be expressed correctly by the above ten dimensionless groups. In, general, however, it is difficult to make all dimensionless groups similar between corresponding experiments due to the temperature dependence of the physical properties of fluid and restrictions of apparatus. In this study the heat loss from water surface could not be equalized from the restrictions of apparatus. Therefore, the similar experiments based on nine dimensionless groups except the heat loss from water surface were undertaken, and influences of the difference of the heat loss on experimental results were discussed carefully. The temperature distributions, decreases of maximum temperatures and volumes within isoconcentration contours showed good agreement between corresponding experiments.. Consequently it was verified that the principle of similarity based on the above mentioned ten dimensionless groups held well, or that the flow of warm water into a rectangular open channel was well expressed by them.

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The nitrogen oxides which are emitted from various kinds of burners or combustion equipments, are injurious to human, plant and animal lives, and also they are, it is believed, caused by the formation of photochemical smog. Some studies have certified that the amount of nitrogen oxides can be considerably reduced by making a modification of the combustion system. In this paper, the authors analyzed the relationship between the mode of combustion, the temperature distribution and the radiant heat transfer characteristic in the combustion chamber and the amount of nitrogen oxides from each steady combustion system, and also studied a certain combusion method by which the amount of nitrogen oxides could be kept to a minimum. By the application of the above method, the small-size gas burner was tested on an experimental basis to confirm its effect as well as to check its adaptability to a household burner for heating use. The test results were summarized as follows: (1) From a viewpoint of designing the burner, the whole premixed-type combusion has an advantage to the diffused-type or partial premixed-type combusion for reducing the amount of nitrogen oxides. (2) From the test result of the whole premixed-type burner, it is found that the maximum temperature in the flame has a great influence on the formation of nitrogen oxides to the others. (3) For reducing the amount of nitrogen oxides, it is effective to use the whole premixed-type burner, thereby to reduce the maximum temperature in the flame, that is to say, to ensure the uniformity of temperature distribution in the combustion chamber by eliminating the local high temperature part. (4) The test burner is of the whole premixed-type and has a structure which is constructed by a cylindrical wire-net for the combustion progressed from outside to inside, a outer casing of heat-resisting crystallized glass for the penetration of radiant heat, and ceramic poles arranged inside the wire-net cylinder. (5) The above test burner has an uniform temperature distribution and a relatively lower temperature level, and it is confirmed that the method is effective to control the formation of nitrogen oxides and to keep its amount in a very small emission rate for the town gas firing. (6) The region of wave lengths on radiant heat from the test burner has the same region of wave lengths on a thermal action near the surface of human skin, and therefore the heating effect from the burner is very moderate to ours. The scope of radiant heat from the test burner and the distribution of its intensity are measured, and the comfortably optimum position where one can warm his body is also settled. (7) When the combustion gas is exhausted from the test burner in a room of 25.5cu. meter at a ventilation rate of 2.5 times per hour, the equilibrium concentration of nitrogen oxides is obtained in 0.025ppm for somewhere around the room.

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The main factors on the environmental side which exert an influence on thermal sensation are temperature, moisture and air movement. The environmental temperature is devided into ambient air temperature and radiant temperature. The former plays a role in convective heat release which is exchanged between the human body and ambient air. On the other hand the latter, namely radiant temperature is a factor which governs the heat loss by radiation from the human body surface. The present paper deals with radiant temperatures. Average radiant temperatures weighted with wall area ratio or with angle factor have been used. In the radiant temperature weighted with area ratio, the difference arising from the location or position of the human body in the room does not appear; this constitutes a drawback in which evaluation of distribution of radiation effect can not be made. In order to remove the drawback of area ratio average radiant temperature which is not a function of position, taking the human body as a minute element, we may consider a means by weighting and averaging by angle factor between the human body and surrounding wall. The radiant temperature weighted with angle factor is different from the radiant temperature weighted by area ratio. The angle factor between the human body and the wall, which is a function of the position, can be decided by only geometrical relation. In the present study, these radiant temperatures were investigated and at the same time a new concept of average radiant temperature and radiative heat transfer coefficient were derived by extending and developing Gebhart's absorption factor. In a closed space, regarding the radiation exchange between the various walls, Gebhart using the absorption factor expressed the results by using the so-called 4th power law on radiation heat exchange. This method is a calculating means which takes into consideration the direct radiation between walls and also the multiplex radiation. The absorption factor defined by Gebhart is mainly a means of expression of radiation heat exchange between walls. The present authors extended this method and applied it to the space between the human body (element) and walls. An attempt was made to linearize from raising the radiation to the 4th power and a radiant temperature and a radiative heat transfer coefficient under a new concept were discussed. The new radiant temperature T_r and the radiative heat transfer coefficient h_r derived are defined by the following equations. T_r=Σ^^n___<i=1>b_iT_i and h_r=ε_sσk in which b_i is the absorption factor between the human body and the surrounding wall, T_i is the temperature of the wall surface, ε_s is the emissivity of the human body surface, σ is the Stefan-Boltzmann's constant and k is the temperature factor which relates to the 3rd power of the absolute temperature. The characteristic feature of the new mean radiant temperature weighted by the absorption factor is that considerations are not only made for the geometric position but also for the emissivity of each wall surface in the absorption factor between the human body and the surrounding walls as the result of consideration of radiant energy balance.

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It is well known that oil film on the water surface suppress evaporation. But it seems that quantitative data on the suppression effect of the oil film are insufficient. In this study experiments on the suppression effect with several oils used broadly in the industries are conducted. The oils used in this experiments are silicon oil, machine oil, gear oil, spindle oil, turbine oil and heavy oil. The evaporation ratio defined as the ratio of the amount of evaporation from the polluted water surface by oil to that from the clean water surface was measured in the laboratry. The evaporation ratio is not the value depends only on the properties of the oil but is affected by many conditions of the atmosphere in the laboratry, namely air temperature, humidity, radiation heat flux at the water surface and so on. Therefore as the property depends only on the oil the evaporation resistance is calculated from the evaporation ratio and is shown. The evaporation resistance differs with oils. Gear oil exhibits the largest evaporation resistance among the oils used in the experiments. But all oils used in the experiments excepting silicon oil have similar characteristics qualitatively. When the mean thickness of the oil film, which is calculated by dividing the volume of the oil by area of the water surface, is smaller than 1〜2μm, the oil film exhibit practically no evaporation resistance, but when the thickness exceeds this value the film exhibits the evaporation resistance distinctly. In this case the evaporation resistance increases in direct propotion to the thickness of the oil film. These oils have nearly equal surface tension, but silicon oil has smaller surface tension. The evaporation resistance of silicon oil increases linearly with the thickness of the oil film from nearly zero film thickness. According to observation the oil forms continuous film when the mean film thickness is larger than 1〜2μm. But when the thickness is smaller than this value, the oil exists in the form of island on the water surface. Thus only when the oil film is continuous, it exhibits the evaporation resistance practically. In the presence of surface activating materials, oil on the water surface coheres. Under this condition it is shown that the evaporation resistance disappears. In order to know the evaporation resistance when air flows over the water surface, basic experiments are conducted in the wind tunnel. It is shown that the evaporation resistance decreases in the presence of air flow. The amount of evaporation from the water surface are affected by the energy budget at the water surface. In this paper the evaporation ratio is calculated numerically under the several conditions which are encountered commonly in the outdoor. Consequently it is shown that to estimate the evaporation ratio calculation of the energy budget is essential under these conditions.

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The function of the air curtain is to suppress the transfer of heat, moisture, dust and smoke through the open doorway. This paper presents both experimental and theoretical investigations on the effect of the cross-flow of the two-dimensional air curtain. Flow Patterns The fluid flow in the neighbourhood of the curtain jet for various cross-flow coefficient α (α=discharge flow at the atmosphere side/nozzle flow) is visualized by water tank experiments with mixing oil particles to the jet fluid flow. This oil particle is made from n-Butyl phthalate 81%, Kerosene 19%, so that the density is as same as water. The interesting results are as follows. (1) As cross-flow coefficient α increases, the flow of the curtain jet divided into the atmosphere side increases, (i.e. its case is called as nonequilibrium condition of jet). (2) In the special case, i.e. α=0, all flow of the jet is forced into the suction side, so that its case is called as equilibrium condition. (3) When we deflect the curtain jet to the suction port side, the value of α becomes gradually small. The free stream which flow out at the atmosphere side, finally passes through beneath the curtain jet, and then the value of α becomes negative. We may call its case as also non-equilibrium condition. (4) The cross-flow region is subdivided into two parts. The first of these is a small region adjacent to the curtain jet, and turbulent diffusion of the cross-flow is dominant in this region. The second region lies between the diffusion region and the atmosphere or the suction port, and the flow in its region behaves like the channel flow, so that its region is termed channel flow. Pressure Characteristics The static pressure distributions on the floor wall and the cross-flow rate have been measured. The pressure of diffusion region are lower than that of channel flow region, in which the pressure seems to be uniform upward. As cross-flow coefficient α decreases, the pressure of channel flow in suction side decreases. In the case of the equilibrium, the pressure difference between the atmosphere side and the channel flow region is from 50 to 70% lower than that between the atmosphere side and the diffusion region. Analysis The curtain jet of the non-equilibrium condition can be classified into two flow patterns; a stagnation point exists floor, or not. Simple flow models for the jet, diffusion and channel flow regions are proposed. And a theoretical analysis is carried out by using the momentum theory around the curtain jets at the equilibrium and non-equilibrium condition. Pressure differences are calculated for several cross-flow rates. The calculated results agree fairly well with the experimental results.

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In the circumstances of the social demand for the residential environment progress and energy saving, we researched for the residential energy consumption and settled the data intend to the next problems. 1) Seizing the energy consumption in the various residences in comparison with their equipment possessions and life styles, we want to know the present state of the residential environment level in Japan. 2) Seizing the share of residential energy, we want to have the basic data for macro estimate of Japanese energy consumption. 3) Seizing the coming residential energy policy, we want to have the basic data for future estimate of Japanese energy consumption. We mention about the quantity of energy consumption in various residences-hourly and monthly electricity, gas and oil consumption in Part 1, and we will analyze the pattern of residential energy consumption in Part 2.

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One of the authors has predicted the facts in his researches as follows: independently of the branching angle and the crosssectional area ratio of the main and the branch pipe it is necessary to give roundness to the upstream end of the joining edges of the main and the branch pipe and to reduce the contraction caused by the separation at that end in order to get the pipe fitting with such rational shape as causes small pressure loss. So the authors practically made pipe fittings with such a shape, and examined whether the above-mentioned prediction is right or not. First, the observations on the flow patterns in laminar flow were made, and the following results were obtained-the fundamental characteristics of the flow in a pipe fitting is not influenced by the roundness at the branch corner, but generally the roundness reduces the contraction caused by the separation coming from the upstream end of the branch corner. Next, the experiments in turbulent flow were made, and the following results were obtained-the pressure loss caused by flow dividing in the main flow is scarcely influenced by the roundness at the joining edges of the main and the branch pipe, and fundamentally it is similar to the pressure loss in a suddenly expanding flow. On the other hand, the pressure loss caused by flow dividing from the main into the branch flow is remarkably reduced by the roundness. The larger the branching angle, the crosssectional area ratio of the main and the branch pipe and the velocity ratio are, the more remarkable the reduction is. Besides, the authors measured the velocity distributions and fluctuations in a right-angled pipe fitting with roundness. According to the results the velocity distributions are very similar to those in a bend. And the roundness makes them even. The roundness at the branch corner reduces the turbulence after dividing in a branch pipe. These are considered to be caused by the reduction of the separation coming from the branch corner due to the roundness there. Therefore the above-mentioned prediction one of the authors made is considered to be substantially right.

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