Computational Study of Flow Interactions over a Close Coupled Canard-Wing on Fighter

There have been many attempts to improve the flying performance of a fighter. By modifying the flow that occurs along the fuselage is expected to improve the performance of the aircraft. One of the indicators of combat aircraft performance is the ability to perform maneuver movement. Adding a canard as forewing on the fighter wing configuration is considered capable of raising the ability in maneuver movement. The use of canard-delta pairs will affect the performance and aerodynamic characteristics of the plane. Wings and canards with delta configuration will make the rolled-up vortex as a lifting force producer on the aircraft. The vortex core formed from the canard and the main wing will interact with each other in maintaining the presence of lift. So, the configuration of the canard and the main wing pairs becomes very important in generating flow interaction patterns. In this research will be analyzed the effect of canard position on aerodynamic character due to the interaction of the flow that occurred. By observing the flow visualization and the aerodynamic forces that occur using computational fluid dynamics techniques (CFD) will get the optimal configuration of the canard position to improve performance fighter aircraft. From the results, obtained canard can increase lift force up to 12%. While the optimum canard position configuration is in front of the main wing of ¼ - ½ the length of the canard chord and has a parallel height of up to ½ canard thick can delay the occurrence of separation up to 5-10 degrees from the maximum angle of attack

Proceedings of the First International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics

1st International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Kruger Park, 8-10 April 2002.This lecture is a principle-based review of a growing body of fundamental work stimulated by multiple opportunities to optimize geometric form (shape, structure, configuration, rhythm, topology, architecture, geography) in systems for heat and fluid flow. Currents flow against resistances, and by generating entropy (irreversibility) they force the system global performance to levels lower than the theoretical limit. The system design is destined to remain imperfect because of constraints (finite sizes, costs, times). Improvements can be achieved by properly balancing the resistances, i.e., by spreading the imperfections through the system. Optimal spreading means to endow the system with geometric form. The system construction springs out of the constrained maximization of global performance. This 'constructal' design principle is reviewed by highlighting applications from heat transfer engineering. Several examples illustrate the optimized internal structure of convection cooled packages of electronics. The origin of optimal geometric features lies in the global effort to use every volume element to the maximum, i.e., to pack the element not only with the most heat generating components, but also with the most flow, in such a way that every fluid packet is effectively engaged in cooling. In flows that connect a point to a volume or an area, the resulting structure is a tree with high conductivity branches and low-conductivity interstices.tm201

Synthesis of new pyrazolium based tunable aryl alkyl ionic liquids and their use in removal of methylene blue from aqueous solution

In this study, two new pyrazolium based tunable aryl alkyl ionic liquids, 2-ethyl-1-(4-methylphenyl)-3,5- dimethylpyrazolium tetrafluoroborate (3a) and 1-(4-methylphenyl)-2-pentyl-3,5-dimethylpyrazolium tetrafluoroborate (3b), were synthesized via three-step reaction and characterized. The removal of methylene blue (MB) from aqueous solution has been investigated using the synthesized salts as an extractant and methylene chloride as a solvent. The obtained results show that MB was extracted from aqueous solution with high extraction efficiency up to 87 % at room temperature at the natural pH of MB solution. The influence of the alkyl chain length on the properties of the salts and their extraction efficiency of MB was investigated

Variation of Soil Structure in the Foot and Toe Slopes of Mt. Vukan, East-central Serbia

This paper presents the variation of soil structure along the foot and toe slopes of Mt. Vukan, East-Central Serbia. The analysis of aggregate size distribution and structure indices were conducted by means of soil units, characteristic soil horizons and elevation differences along the study area. Soils of Great Field located at different elevations were found to have significant variation in ASD and soil structure indices. Topsoil horizon of Eutric Cambisols have higher MWD after dry sieving, but at the same time it has the highest variation in MWD after wet sieving, indicating low water stability, which is opposite to the coefficient of aggregability. We share an opinion that change in MWD better depicts soils structure stability to water. The results of correlation analysis indicated that clay content is correlated more to structure indices compared with SOM content. SOM is significantly correlated with ASD and soil structure indices only in Calcomelansols, whereas the significant correlation of clay content and soil structure is more evident in Eutric Cambisols and Non-calcaric Chernozems, compared with other soil units. Soil structure variation along the lowest chain of Catena might be strong, and that it has to be analyzed from the point of view of soil unit and their corresponding soil horizons

IMPACT OF GRAZING ON SOIL ORGANIC MATTER AND PHYSICAL PROPERTIES OF A FLUVISOL IN NORTWEST SERBIA

The effects of long-term (>20 yr) grazing on the selected physical properties of a non carbonated silty-clay Fluvisols were studied in the region of the Kolubara Valley, Northwest Serbia. Two adjacent land-use types (native deciduous forest and natural pasture soils converted from forests for more than 20 years) were chosen for the study. Disturbed and undisturbed soil samples were collected from three sites at each of the two different land-use types from the depths of 0–15, 15–30 and 30–45 cm. In relation to the soil under native forest, soil organic matter content, total porosity and air-filled porosity were significantly reduced after long-term of grazing. The bulk density (0.99–1.48 g cm–3) and the saturated hydraulic conductivity (6.9.10–2–3.2.10–4 cm s–1) were significantly lower in forest compared to the adjacent pasture (ex-forest) soil (1.49–1.55 g cm–3 and 3.4.10–4–5.5.10–4 cm s–1, respectively). In addition, forest had significantly lower dry mean weight diameter (7.0–9.2 mm) and greater wet mean weight diameter (2.0–2.6 mm) for 0–45 cm depth compared with the pasture (8.8–9.4 mm and 1.8–2.3 mm, respectively). The decrease of soil organic matter content and reduction in aggregate stability under long-term grazing rendered the soil more susceptible to compaction. In conclusion, the results of this study indicate that removal of permanent vegetation in the conversion process from forest areas to pasture land may lead to loss of soil productivity and serious soil degradation. Obviously, there is a need for greater attention to developing sustainable land use practices in management of these ecosystems to prevent further degradation of pasture soils in the region

Water productivity indices of the soybean grown on silty clay soil under sprinkler irrigation

The objective of this research was to compare the effects of different irrigation treatments on soybean [Glycine max (L.) Merr.] productivity and water use efficiency on experimental fields of the Maize Research Institute of Zemun Polje(Serbia), in 2007 and 2008. Four irrigation levels were investigated: full irrigation (I100), 65% and 40% of I100 (I65 and I40) and a rain-fed (I0) system. The crop water use efficiency (CWUE, also known as crop water productivity –CWP), irrigation water use efficiency (IWUE) and evapotranspiration water use efficiency (ETWUE) were used to assess the water productivity of each studied treatment. The efficiency of the same treatment differed between the years as it depended on seasonal water availability, weather conditions and their impact on seed yields. Maximum and minimum yields were obtained in the I65 and I0 treatments, averaging 3.41 t ha–1 and 2.26 t ha–1, respectively. Water use efficiency values were influenced by the irrigation levels. In general, CWUE values increased with the increased level of irrigation. In both growing seasons, IWUE and ETWUE decreased with increasing the seasonal water consumption and irrigation depth. On average, treatments I40 and I65 resulted in similar or higher CWUE and ETWUE than I100, in both growing seasons. I65 resulted in the highest IWUE, averaged over the two seasons, while I100 had the lowest IWUE. I65 could be proper for the soybean irrigated in Vojvodina when there is no water shortage and I45 could be used as a good basis for reduced sprinkler irrigation strategy development under water shortage

Прикладна фізика : українсько-російсько-англійський тлумачний словник. У 4 т. Т. 2. З – Н

Словник охоплює близько 30 тис. термінів з прикладної фізики і дотичних до неї галузей знань та їх тлумачення трьома мовами (українською, російською та англійською). Багато термінів і визначень, наведених у словнику, якими послуговуються у відповідній галузі знань, досі не входили до жодного зі спеціалізованих словників. Словник призначений для викладачів, науковців, інженерів, аспірантів, студентів вищих навчальних закладів, перекладачів з природничих і технічних дисциплін

1990-1995 Brock Campus News

A compilation of the administration newspaper, Brock Campus News, for the years 1990 through 1995. It had previously been titled The Blue Badger