Determining Position of the Evaporator in a Smart Classroom Concept Using CFD Method

Various, different evaporator placements in a room have produced different airflow patterns, temperature distribution, and airflow velocities. In this study, the average room temperature and airflow velocity measured at 27 points of the CFD simulation for 4 positions of the planned evaporator placements were compared to determine the most ideal position based on the comfortable temperature and the maximum airflow velocity pursuant to the SNI 03-6572-2001 recommendation. On Position 1, two evaporators were given to the west wall. Position 2, two evaporators were placed on the south wall. On Position 3, two evaporators were given to the north wall. Moreover, on Position 4, two evaporators were placed opposite to each other where an evaporator was placed on the south wall, and the other evaporator was placed on the north wall. An ANSYS Fluent software was employed to make the CFD simulation. Based on the results of the study, it was found out that Position 2 was the most ideal evaporator placement position since it met the comfortable temperature limit and has the highest number of airflow velocity points meeting the recommended maximum airflow velocity pursuant to the SNI 03-6572-2001 recommendation.

Discussion on the Painting in Cave 254 of Mogao Grottoes

Cave 254 of the Mogao Grottoes is one of the most representative grottoes from the Northern Wei Dynasty. The painting of “Laying Down Oneself to Feed the Tiger” on the south wall of the grotto has high artistic value. With changing dynasties and the development of time, the original appearance of the painting has changed. In particular, the color of the whole cave has undergone a subversive change, resulting in many misunderstandings. In this article, the composition, colors, and lines of the painting, “Laying Down Oneself to Feed the Tiger,” are discussed in view of the current situation of the cave, and the work is approached from the perspective of painting. The concept of different times of the same painting, its precise and unique layout, as well as development peak of “Laying Down Oneself to Feed the Tiger” are expounded. In this article, the unique artistic level of this mural in the Northern Dynasty is demonstrated along with its importance for present paintings.

I. Deir el-Bahari 196 (partly) supplemented

The article presents a fragment of the cornice from the Ptolemaic Portico of the Hatshepsut temple at Deir el-Bahari discovered in 2021 in the fill of the Middle Kingdom tomb MMA 28. The fragment carries remnants of two dipinti in red ochre, of which one is illegible and the other preserves vestiges of the three first lines of the Greek inscription I. Deir el-Bahari 196. They show that the inscription was a proskynema (act of adoration) addressed to Amenothes (Greek for Amenhotep son of Hapu). The name of the author cannot be read with certainty (perhaps Pe[---]); the text also mentions a certain Menodoros, who may be the father of the protagonist of the inscription or another man. In an appendix, a fragment of another text in Greek, probably originating from the south wall of the Bark Room of the main sanctuary of Amun is presented.

Numerical Study on Energy-Saving Performance of a New Type of Phase Change Material Room

The thermal performance of a phase change energy storage building envelope with the ventilated cavity was evaluated. CaCl2·6H2O-Mg(NO3)2·6H2O/expanded graphite (EG) was employed to combined with the building for year-round management. The energy consumption caused by the building under different influence parameters was evaluated numerically. The results indicated that CaCl2·6H2O-8wt %Mg(NO3)2·6H2O/EG should be installed on the south wall for the heating season, while CaCl2·6H2O-2wt %Mg(NO3)2·6H2O/EG should be integrated on the roof for the cooling season. When the air layer was ventilated and the south wall was coated with the solar absorbing coating, the room could save approximately 30% of energy consumption. Moreover, the energy consumption increased with an increase in the air layer thickness, and the air layers played a different role in the building envelope. The optimal value of the flow rate between air layer 2, air layer 3, and the room was 0.09 m3/s. To reduce the energy consumption, the phase change materials (PCMs) with large and small thermal conductivity should be installed in the south wall and roof, respectively. In general, the phase change energy storage building envelope with the ventilated cavity can save energy during the heating and cooling seasons.

On the dynastic cult of the rulers of Bukhara Sogd in the Early Middle Ages (to the interpretation of the murals of the Varakhsha palace)

Varakhsha hillfort is located in the Bukhara oasis (Uzbekistan). From the 6th to 8th c., it was the residence of the rulers of Bukhara Sogd. Archaeological investigations of the Varakhsha were carried out in the late 1930s, and then later in 1947 and 1949–1954. During the excavations of the palace, wall paintings were discovered in the Red (Hindu) and East (Blue) Halls (7th–8th c.). In the East Hall, the center of the art composition on the south wall was dominated by a massive figure of a ‘king’ with a golden sword, seated on a throne with protomas of winged camels. Depicted next to him was a group of five people sitting on their knees — the king's family. The elder man is making an offering to the fire on an altar. On the base of the altar, there is a male figure, seated on a throne in the form of a lying camel. This figure represents Vretragna, the Avestan deity of Victory. Mythogenically, Vretragna is close to the Vedic god of thunder Indra. In Avesta, Vretragna appears in various guises: a Bactrian camel; the bird of prey Varagn; a man with a golden sword. In Sogdian iconography, the image of the Bactrian camel is most often associated with Vretragna. The characters of the murals in the Blue Hall (the king’s family) bring offering to the fire lit in tribute to the deity — to Vretragna. The central figure of this composition was identi-fied by V.A. Shishkin as a king. In our opinion, it rather depicts Vretragna. This is implicitly indicated by the protomas of the throne in the form of winged camels and by the image of ‘the king with the golden sword’. The walls of the Red Hall of Varakhsha were decorated with a scene of hunters riding elephants. Each elephant was ridden by a servant-mahout and a lord, whose figure would be disproportionately large. They are slaying huge monsters. According to researchers, an image of the Sogdian deity Adbag is repeated here. The epithet ‘Adbag’ — ‘Supreme deity’ is associated with Ahuramazda. B.I. Marshak and A.M. Belenitsky note, that here Adbag-Ahuramazda is likened to Indra riding a white elephant. It seems to us quite probable that such an epithet could be applied to various gods of a high status. Notably, it could be Vretragna depicted here, who is akin to Indra. We think that the image of Vretragna held a special place in the visual arts of Varakhsha, as the patron deity of the Bukhar-Khudat dynasty. He was depicted in the center of the com-position in the Blue Hall in his Avestan hypostasis, and in the Red Hall he was depicted in the form of Indra.

Research on Energy-Saving Design of Rural Building Wall in Qinba Mountains Based on Uniform Radiation Field

How to create a healthy and comfortable indoor environment without causing a substantial increase in energy consumption has become a strategic problem that the development of all countries must face and solve. According to the climatic conditions of Qinba Mountains in China, combined with the characteristics of local rural residential buildings and residents’ living habits, the field survey and theoretical analysis were used to study the thermal environment status and the heating energy consumption condition of local rural residential buildings. The thermal design method of walls for the local rural energy-saving buildings based on the indoor uniform radiation field was explored by using the outdoor comprehensive temperature function expressed by the fourth-order harmonic Fourier series as the boundary condition of the wall thermal analysis. ANSYS CFX was adopted to study the suitability of the energy-saving wall structure designed by the above method. The results show that the indoor thermal environment of local rural residential buildings in winter is not ideal and the heating energy consumption is high, but this area has the geographical advantage to develop solar energy buildings. It is proposed that the indoor thermal comfort temperature of local rural residential buildings in winter should not be lower than 14°C. When the internal surface temperature of the external walls in different orientations are equally based on the design principle of uniform radiation field, the heat transfer coefficient of the east wall, the west wall, and the north wall of the local rural residential buildings is 1.13 times, 1.06 times, and 1.14 times of the south wall heat transfer coefficient, respectively. The energy-saving structural wall with KPI porous brick as the main material and the south wall heat transfer coefficient of 0.9 W/(m2·K) is the most suitable energy-saving wall for local rural residential buildings.

Thermal Efficiency for Passive Solar Chimney with and Without Heat Storage material

In this study, a different design of passive air Solar Chimney(SC)was tested by installing it in the south wall of insulated test room in Baghdad city. The SC was designed from vertical and inclined parts connected serially together, the vertical SC (first part) has a single pass and Thermal Energy Storage Box Collector (TESB (refined paraffin wax as Phase Change Material(PCM)-Copper Foam Matrix(CFM))), while the inclined SC was designed in single pass, double passes and double pass with TESB (semi refined paraffin wax with copper foam matrix) with selective working angle ((30o, 45o and 60o). A computational model was employed and solved by Finite Volume Method (FVM) to simulate the air induced through the test room by SC effect. The governing equation of Computational Fluid Dynamic (CFD) model was developed by the effective heat capacity method equation to describe the heat storage and release from PCM-CFM. Practical and computational Results referred to increase in thermal conductivity of the paraffin wax that supported by CFM than 10 times, while the ventilation effect is still active for hours after sun set amount. The maximum ventilation mass flow rate with TESB collector was 36.651 kg/hr., when the overall discharge coefficient equals 0.371. Also, the experimental results referred to the best working angle range 45~60o, while the highest approaching temperature (between air and collector) was appeared for the double passes flat plate collector. Results gave higher heat storage efficiency 47% when the maximum solar radiation 780 W/m2 at 12.00 pm, and the energy summation through duration of charging time was 18460 kJ. Double passes SC at 60o angle presented the highest efficiency with value approaching to 73%, while TESB collector efficiency depicted highest efficiency value 70% at 12:00 pm.

Preliminary Stability and Resistance Analysis of the Cheops Boat

The Cheops Boat is the most complete, largest, and one of the oldest boats ever excavated, but it has received surprisingly little study by Naval Architects. The 43-m boat was constructed around 2500 BC and placed, disassembled, in a pit next to the Great Pyramid at Giza in Egypt. Since its discovery in 1954, there has been speculation about its original design, means of propulsion, and purpose. This article presents previously unpublished results of the first tank testing of a model of the Cheops Boat and some preliminary conclusions about the design, propulsion, and function of the original. It is shown that the stability characteristics of the boat make it suited for carrying lightweight cargo and people in the protected waters of the Nile. Towing tests have shown that the boat can be safely rowed in a variety of wind and current conditions. Windward sailing calculations have shown that, if fitted with sail, then boats such as the Cheops Boat perform well downwind, but sail no closer than a beam reach. During the 1954 clearing of debris from the Giza Plateau, it was noticed that the Great Pyramid's north and west enclosure walls were 23.6m from the base of pyramid, but the south wall was 5mcloser to the base. Careful inspection revealed that the south wall had been built in an asymmetrical location to conceal two boat pits beneath it. The two pits were end to end, one covered by 41 massive limestone blocks and the other by 40. When the eastern pit was opened, the remains of the disassembled boat were revealed. Figure 1 shows photographs of some of the pieces as they were removed from the pit. Remarkably, the 4500-year-old cedar had been so well preserved that it was possible to reassemble this boat like a kit. Even the rope was preserved, and looked like what could be bought today.

Electronic equipment measuring device for heat quantity through a flat wall

In the paper, an experimental study for calculation the heat quantity through a flat wall by electronic system has been presented. The aim is temperature measurement on outer and inner walls of a room for 20 days at 1-minute interval of measurement. A transient regime has been considered. The data measured has been collected on a non-insulated south wall of a Technical University of Varna campus building. The wall layers parameters have to be known for the choice of surrounding area. In order to reduce errors of the outer side of wall temperature measurement caused by the solar radiation, the temperature sensor has been painted grey. The experimental equipment for the heat quantity measurement consists of two plates, each with 4 temperature fixed in a rectangle. The sensors are situated in а flat area in order to obtaining more precise results of experimental study. The problem has been solved by finding decision of the classic heat conduction equation. The experimental temperatures are treated by microprocessor’s platform based on Arduino board. As a result, the average temperature of each plate with sensors has been estimated.

Experimental Study of Using Thermal Insulation In Buildings Walls To Reduce Heating Load In Al - Kut City

Experimental study has been carried out on a small room model constructed from sandwich panel in Al-Kut city to reduce the heating load in winter season. Three types of thermal insulation were used; (Glass wool, Air gap and Sawdust). The room model dimensions were (2m length x2m width x2.4 m height). Room's south wall includes two openings of 0.3m width, 1m height. The first opening is closed by common bricks only, while the second opening is built with double walls from brick separated by thermal insulation of thickness 2cm. The results show that the maximum energy saving of heating load at night time when using thermal insulation were.69%, 58.4%, and 53.6%for glass wool, sawdust and Air gap respectively.