Engineering civilization brought convenient and comfortable life to us. However, some environmental problems such as various pollutions have also been developed with it. Acoustical noise is one of the major problems in modern life. Noise is generated from a noise source and propagates through transmitting medium such as the air and eventually reaches a receiver, usually a human being. The noise problem can be avoided, therefore, if one of those three elements in the noise problem is removed completely. In actual case, engineers are looking for most efficient way combining the controls for these three elements. In this article, basic characteristics of noise is reviewed briefly at first, then sound field analysis to predict sound transmission is discussed Aerodynamic noise is one of the major problems in silence amenity engineering today. Basic concept of the aerodynamic noise generation mechanism is discussed in detail with applications to turbo-machinery and high speed train noise control technology.

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The fault detection and diagnosis system, the FDD system, for the HVAC was initiated around the middle of 1970s in Japan but it still remains at the elementary stage. The HVAC is really one of the most complicated and large scaled system for the FDD system. Besides, the maintenance engineering was never focussed as the target of the academic study since after the war, but the FDD system for some kinds of the components and subsystems has been developed for the sake of the practical industrial needs. Recently, international cooperative study in the IEA Annex 25 on the energy conservation for the building and community targetted on the BOFD, the building optimization, fault detection and diagnosis. Not a few academic peaple from various engineering field got interested and, moreover, some national projects seem to start in the European countries. The author has reviewed the state of the art of the FDD and BO as well based on the references and the experience at the IEA study.

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In the case of fish body assumed a circular colume (cylindrical body) the calculation of the inside pressure and stress at frozen part of fish body during freezing were carried out on freezing of tuna fish by "-45°C CaCl₂ brine immersion system (B1)", "-45°C air blast system (A1)" and "-45°C still air system (A2)".
The results of calculation were made clear that the inside pressure and stress of the frozen part of tuna fish body by "B1" and "A1" showed the same tendency, and the circumferential stress at outside frozen tuna body were larger than inside stress, but the difference of circumferential stress between outside and inside frozen body of "B1" was reached about 30 times by "A1" at r_i=0.5, and "A2" showed different tendency from "B1" and "A1", the circumferential stress of outside frozen tuna body was almost smaller than inside stress.
Then, it was in a larger possibility that "-45°C CaCl₂, brine immersion system" gives rise to gape on the frozen tuna body during freezing than "-45°C air blast system" and "-45°C still air system".

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This paper investigates a heterogeneous nucleation of supercooled water on foreign particles. The ultra pure water in an acrylic tank is cooled by the upper side heat transfer disk and freezing temperatures are measured where the particle concentration is varied. The property of the particles is explained by a surface parameter. It is assumed that the supercooled water will freeze when the number of nuclei in the supercooled water reaches 1. Freezing temperatures are calculated using the surface parameters and the experimental results are compared with the calculated results. The freezing temperatures rise as the particle concentration is higher. The model of nucleation by aggregation of foreign particles is proposed and the reason for the rising of freezing temperatures is showed.

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For purposes such as freezing and ice accumulation which require temperatures below 0 degrees, ammonia-water absorption refrigerator is being looked at once again. If used for these purpose, it is usually driven all through the year. In this case, cooling water inlet temperature which greatly influences absorption cycle changes very widely. So in such conditions, it is hoped to be driven high efficiently. And ammonia's charging quantity is required as small as possible on account of poisonous. But when it driven all through the year, ammonia charging quantity influences the efficiency greatly. So this research aims to clarify the ammonia charging quantity with which ammonia-water absorption refrigerator can be driven high efficiently.
So static simulation model was made. By using this tool, we investigated the influence of cooling water inlet temperature on COP, solution concentration. As a result, minimum ammonia charging quantity with which ammonia water absorption refrigerator can be driven was obtained.

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Convective heat trsnsfer from an open cavity has been studied in the range of Reynolds numbers from 10⁴ to 10⁵ in the case of the depth-to-width ratio H / L= 1.5 by numerical calculation Convective heat transfer from an open cavity is treated by the following two phenomena; one the heat transfer related to the temperature difference the wall and the fluid in the open cavity, the other the heat transfer related to the temperature difference between the fluid in the open cavity and the external main stream. In part 2, effect of temperature non-uniformity on the wall surface for convective heat transfer in the case of the depth-to-width ratio H/L= 1.0 is studied by the numerical calculation of heat transfer model. In the present report, effect of temperature nonunifomity on the wall surface for convective heat transfer in the case case of the depth-to-width ratio H/L = 1.5 is studied by numerical calculation of heat transfer model. Heat transfer rate obtained by numerical calculation almost coincide with the existing experimental data obtained under the conditions that there is temperature non-uniformity on the wall surface of the open cavity which is made of copper.

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Recently, from a view point of the environmental protection, NH₃-H₂O absorption refrigerator attracts attention in the field of the refrigeration and the air conditioning. Since NH₃-H₂O absorption refrigerators can produce below zero degree products, this type of refrigerators have many usages in the refrigeration.
This paper describes the two-stage desorption type absorption refrigerator driven by waste heat of co-generation system. There are two absorption cycles which are operated under the condition of the different pressure and the solution concentration in this absorption refrigerator. It becomes essential to clarify the characteristics of this absorption refrigerator since the operating conditions are changed through out the year in the co-generation system. Particularly, in this paper, we investigate the effects of evaporating temperature of ammonia and cooling water temperature for the performance of this absorption refrigerator by simulation analysis. Through out the research, it is shown that COP can be improved when evaporating temperature is higher or cooling water temperature is lower. In addition to this, it is obtained that the necessary temperature of hot water becomes lower in such condition. As a result, the effectiveness of using this absorption refrigerator under the operating condition of which hot watertemperatureis90∼100[°C] and evaporating temperature is -10∼- 20 [°C] is clarified

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Different from H₂O-LiBr absorption cycle, it is necessary to have rectifier between generator and condenser in NH₃-H₂O absorption cycle, because there mixes some steam in refrigerant vapor in the process of regenerating refrigerant from the ammonia strong aqueous solution. And in some case ex. partial load or heating, the efficiency of rectifier might decrease, if the flow rate of refrigerant vapor and ammonia aqueous solution decrease. As a result, steam flow into condenser with ammonia refrigerant vapor, which reduces cycle COPs of cooling and heating.
Accordingly in order to evaluate the effect of ammonia concentration in refrigerant for the performance of NH₃-H₂O absorption heat pump, the simple design approach of modeling condenser and evaporator is introduced in this paper. In the model, the calculation of heat rate in condenser and evaporator was simplified considering the characteristic of NH₃-H₂O liquid-vapor equilibrium. Then the simulation for cycle perforance based on GAX absorption cycle was made using the efficiency of rectifier that established the ammonia concentration in refrigerant and it was derived that 3 [%] decrease of ammonia concentration in refrigerant induced 15 [%] decrcase of cooling COP and 7 [%] decrease of heating COP and that there existed the most suitable circulation ratio for each ammonia concentration in refrigerant.

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In this research, the investigation on the characteristics of the unsteady state phenomenon of the direct contact melting at the initial stage was carried out analytically, where the system starts to form a liquid film between the solid surface and the heating plate. Three types of heating conditions were examined. One was to have a constant heat flux at the top surface of the heating plate, the next was to have the constant heat flux at bottom surface of the heating plate, and the last was to have the constant heat transfer coefficient at the bottom surface of the heating plate. The difference in phenomena under three conditions were pointed out. Furthermore, various parameters such as the size of the heating plate, the thermal physical properties of the heating plate, the size and the thermal physical properties of the PCM, were varied for each condition, and the effect of each parameter was investigated. The results were summarized qualitatively at two points: one was the melting speed at the steady state, and the other was the time required to approach the steady state.

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Thermophysical properties of water were studied using molecular dynamics method. Various types of models for water molecule were selected and the results were compared. The simulation was carried out using NPT ensemble, and the pressure was fixed at atmosphere. There is a close relationship between thermophysical properties and the solidification process of supercooled water. In this report, heat capacity, thermal expansion coefficient, isothermal compressibility, self-diffusion coefficient, shear viscosity and thermal conductivity were calculated using various models in the range from normal temperature down to supercooled temperature. Addition to these properties, the latent heat of ice Ih to water was estimated. The models selected in thies report were ST2, TIP4P, CC and SPC/E. When the temperature was high, good agreement was found between each models and the experimental data for almost all properties. However, at low temperature region, the difference from experimental data exists depending on the choice of water models, and all these models in the lowest temperature behave as a solid state. By carrying out the melting simulation of ice Ih under atmospheric pressur using these models, melting points were found to be relatively high compared to the real water, but the latent heats were estimated to be close enough to the experimental data.

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