Teruyuki Fukuhara

A New Approach to Modeling Vehicle-Induced Heat and Its Thermal Effects on Road Surface Temperature

The distribution of vehicle-induced wind velocity in the transversal direction of roads is measured. A statistical analysis is also performed to find the vehicle stopping time and stopping position at traffic signals. These results are used to build a heat-balance model to predict the road surface temperature resulting from the thermal effects of vehicles. To validate the model, measured and calculated road surface temperatures for a free-running (single path) location and a traffic-signal location are compared. The contributions of meteorological and vehicle-induced heat fluxes to the road surface temperature are quantitatively analyzed. For the present traffic and meteorological conditions, the calculated and measured road surface temperatures were in agreement for both the free-running and traffic-signal locations. Furthermore, the thermal contribution of vehicles to the road surface temperature was found to be nonnegligible at both locations.

Evaporativity and Productivity of a New Tubular Solar Still

A Tubular Solar Still (TSS) has being developed by our research group and a transparent vinyl chloride sheet of 0.5mm in thickness was used for the tubular cover of the first model designed by Islam KMS (2007). Since then we have been improving the first model from the viewpoint of assembly, economy and maintenance. A polythene film of 70µm in thickness was, therefore, adopted as the cover of the second model. As a result, the cover weight of the second model was one twelfth lighter than that of the first model. An experiment was carried out to investigate the evaporation and production performance of the second model and the thermal properties of the tubular cover, humid air and water in a trough inside the still. It was revealed that the hourly evaporation and production fluxes became a little lower for the second model than the first one under the same conditions of ambient air temperature and relative humidity and radiant heat flux. One of the reasons would be the difference in the water depth between the two experiments. Another possible reason of reducing the productivity would be the stagnant of the condensed water due to the undulations of the polythene film.

Cost and production performance of a Tubular Solar Still

In this paper, the design, fabrication, cost and distilled water production (production) performance of a Tubular Solar Still (TSS) is presented. Since the TSS cover and trough are made of cheap and locally acquisitioned lightweight materials, the TSS can be formed into a desirable size easily. Thus, the weight per unit length is 0.65kg/m and it is expected that the production cost is about 484/m3(~US

Effects of Gravel and Date-Palm Mulch on Heat Moisture and Salt Movement in a Desert Soil

5/m3). A field experiment on the production performance of the TSS was carried out in the United Arab Emirates and the effects of initial saline water volume (water depth) in the trough on the daily production were examined in terms of the use and management of the TSS. The daily production is inversely proportional to the water depth, as far as the water depth is 0.04m or less. The main reason is attributed to the production performance after the evening or sunset due to remaining solar heat (designated as “production inertia”). It is seen that contribution of the production inertia to the daily production cannot be disregarded and that the water depth is one of key parameters to control the production performance of the TSS.

Diurnal fluctuations of soil temperature, vapor pressure and evaporation in bare soils

The control performance of evaporation from the soil surface and of the soil surface temperature by gravel mulch (GM) and date-palm mulch (DM) was discussed in this paper. A heat, moisture and salt movement experiment was carried out using soil columns in the United Arab Emirates. Elapsed time, when 50% of irrigation water was lost due to evaporation, was remarkably prolonged by mulching, e.g. 2.3 times for the GM and 3.4 times for the DM, respectively, compared with that for bare soil (BS). The daily maximum soil surface temperature was 5.0°C lower for the DM than the BS, but there was little difference between the GM and the BS. The time rate of salt accumulation near the soil surface was reduced by mulching. For example, the salt mass content of the soil surface, S c surf , for the BS became higher than the initial S c surf (=0.4%) 48 hours after watering. On the other hand, S c for the DM was lower than the initial one at the same elapsed time. It was concluded that the reduction of evaporation by mulching with date-palm chips and gravels is effective in delay of the salt accumulation near the soil surface.

Effect of Heat-Reflective Insulation Coating of Building Energy Saving in Summer

In order to better understand post-irrigation drying phenomena, micro-meteorological observations and heat and moisture transfer measurements in soil under bare surface conditions were carried out in the United Arab Emirates (U.A.E). Soil temperature, relative humidity in soil pores and volumetric water content were measured by thermo-hygrometers and thermal conductivity probes.

Study on Energy Saving Effect of Heat-Reflective Insulation Coating on Exterior Walls of Building in Summer

In order to discuss the effect of energy saving of heat-reflective insulation coating on exterior walls of building, the wall temperature change of two test rooms with heat insulation or not in Hangzhou has been monitored in summer, and the heat flux data of east, south and west walls were analyzed. The results indicate that the reflective coatings reduce the exterior surface temperature by up to 7 to 8°C. The reduction in heat gain of east, south and west walls is significant, which is the cooling effect. The total surface heat gain of exterior walls without reflective coatings is 2.44 times larger than those without them. In particular, the heat gain of walls with reflective coatings is nearly 5.27 times more than that of walls without reflective coatings. The reduction in electricity consumption of air-conditioning system in the building with reflective coatings is 2.5KWh/m2 per month by calculation, which well proves the energy saving effect of reflective coatings.

Applicability and Thermal Consideration of a Single Layered Model for Snow/Ice Condition on a Road

This paper presents an experimental study on the energy saving effect of reflective coatings on exterior walls. Two identical test buildings were built in Zhejiang College of Construction, one of which is covered with reflective coatings and the other not. The wall temperature fluctuation of both buildings is monitored in summer, which includes the east, south and west walls. The results indicate that the maximum reduction of wall temperature is 9-10 °C in the building with reflective coatings, compared with wall temperature in the other without it. The reduction in heat gain of east, south and west walls is obvious, so is the cooling effect. The reduction in electricity consumption of air-conditioning system in the building with reflective coatings is 0.94 KWh/m2 per month times by calculation, which well proves the energy saving effect of reflective coatings.

ESTIMATION OF EVAPOTRANSPIRATION RATE AND DRAINAGE WATER QUALITY FROM VEGETATION ON ROOFTOP BASED ON METEOROLOGICAL AND HYDROLOGICAL OBSERVATION

A heat and moisture transfer model for predicting the melting process of a snow/ice layer on a road is proposed in the present paper. Since the snow/ice layer is thin, 50mm or less, it is assumed to be uniform the model. The model is, therefore, called a ‘single layered model’.It was found from the sensitivity analysis that (1) a calculation error becomes large for the thickness of the snow/ice layer more than 20mm, (2) the albedo and emissivity have stronger effect on the snow melting rate rather than the transmissivity and thermal contact resistance between the pavement and the snow/ice layer.

INJECTION AND EXTRACTION OF GROUND HEAT BY BORE-HOLE HEAT EXCHANGE SYSTEM AND KONG PERIOD THERMAL INTERACTION BETWEEN GROUND AND BORE-HOLE

近畿大学に屋上緑化区画および微気象・水文観測システムを構築し, 蒸発散量の実測による緑化屋上における植生維持に必要な水量の算定, および緑化区画からの排水の水質調査を試みた. その結果, 以下のことが明らかとなった. (1) 今回の観測より得られた夏季における芝の屋上緑化区画からの日蒸発散量は, 4.4mmおよび6.2mmであった. (2) 緑化区画からの排水には, 除草剤・肥料に起因するもののみならず, 今回使用した人工土壌に起因すると思われる硝酸・亜硝酸態窒素およびリン酸態リンが含まれていた. (3) 屋上緑化区画からの排水水質を, 最も厳しい基準である水域類型Iの湖沼の水質環境基準値と比較すると, 硝酸・亜硝酸態窒素濃度は7～10倍程度, リン酸態リン濃度は800～1400倍程度であった.