An Analysis of Aerodynamic Design Issues of Box-Wing Aircraft

The potential of the joined/box-wing aircraft as an environmentally friendly airliner that is capable of meeting current and future emission thresholds led to the investigation of this concept. This study reviews the evolution and current trends in the aerodynamic design of the box-wing aircraft with specific emphasis on box-wing theory, airfoil characteristics, and aerodynamic issues of the box-wing aircraft. The study was undertaken to highlight the distinct features of the box-wing configuration which make it very attractive for future airliners. The study reveals that the box-wing aircraft possesses a significant aerodynamic advantage over conventional aircraft. The box-wing aircraft configuration is also a less radical departure from the conventional concept. It thus could be developed with existing tried-and-tested aircraft design technologies, methodologies, and processes. Hence this article is a commentary that highlights the enormous potential of the box-wing aircraft and the need for further studies in this research domain

The GENUS aircraft conceptual design environment

The design of aircraft has evolved over time from the classical design approach to the more modern computer-based design method utilizing multivariate design optimization. In recent years, aircraft concepts and configurations have become more diverse and complex thus pushing many synthesis packages beyond their capability. Furthermore, many examples of aircraft design software focus on the analysis of one particular concept thus requiring separate packages for each concept. This can lead to complications in comparing concepts and configurations as differences in performance may originate from different prediction toolsets being used. This paper presents the GENUS Aircraft Design Framework developed by Cranfield University’s Aircraft Design Group to address these issues. The paper reviews available aircraft design methodologies and describes the challenges faced in their development and application. Following this, the GENUS aircraft design environment is introduced, along with the theoretical background and practical reasoning behind the program architecture. Particular attention is given to the programming, choice of methodology, and optimization techniques involved. Subsequently, some applications of the developed methodology, implemented in the framework are presented to illustrate the diversity of the approach. Three special classes of aircraft design concept are presented briefly

Prediction of the Optimal Reaction Temperature of the Riser of an Industrial Fluid Catalytic Cracking (FCC) Unit

A pseudo homogeneous two-dimensional (2D) model of an industrial Fluid Catalytic Cracking (FCC) riser is here presented. The FCC riser models of previous researchers were mostly based on the assumption of negligible mass transfer resistance and 1D plug flow. These assumptions undermine the accuracy of the models by over-predicting the optimum residence time of the riser. In this work the coke content of FCC catalyst was modeled as a function of the reactor temperature with the aim of predicting the operating conditions that will reduce coke on catalyst without undermining the yield of the key product (gasoline). Mass transfer resistance was incorporated in the reactor model to enhance the accuracy of the results. Catalyst deactivation was modeled based on the exponential decay function. The mass transfer coefficient and the catalyst effectiveness factor were estimated from empirical correlations obtained from literature. Data used for the simulation were sourced from an existing plant (KRPC) as well as from open literature. Finite difference numerical scheme was used to discretise the model governing equation. At the end of the investigation, three different operating temperature regimes were identified from the simulated results for the coking of FCC catalyst (low temperature, optimal temperature and high temperature regimes). An optimum operating temperature range of 786K-788K and an optimum catalyst-to-oil ratio (COR) range of 4.60-4.71 were predicted for the riser. Keywords: FCC; Finite difference, Mass transfer resistance, Catalyst deactivation, Riser models.

Determination Of Lipid Contents Of Two New Soy Bean Cultivars Using Gas Chromatography – Mass Spectrometry (GC-MS)

Determination of fatty acids and sterols in oil is very important as they serve as the vital indicators of the activity and purity, respectively of the oils. A qualitative Gas Chromatography – Mass Spectrometry study of oils from soy beans of two varieties (TGX 1802-1F, and TGX 1019-2EB) was done to determine their fatty acid, sterol and other compositions. The oils were extracted with n-hexane and concentrated in vacuo using rotary evaporator at 45 oC. The oils were slightly soluble in ethanol, insoluble in water and acetonitrile, and readily soluble in n-hexane, acetone, chloroform and benzene. The oils were preliminarily characterized using iodine value, acid value, specific gravity, volatile matter, saponification value and peroxide value. The acid values were 0.60 and 0.59 respectively, while the specific gravity at 30 oC was 0.919 for both samples. The volatile matters were 0.19 % and 0.17 %, and the peroxidevalues were 9.2 and 9.8 mEq/Kg respectively. Using an Agilient series 6890 Gas Chromatography system with a 5973 mass selective detector, the lipid composition of these oils was studied. Both cultivars were found to contain linoleic acid and pentadecadienoyl octadecadienoate. Palmitic acid and stearic acid were found in TGX 1802-1F, while TGX 1019-2EB was found to contain cholesterol and methyl octadecadienoate. This implies that TGX 1802-1F will be safe in applications where cholesterol free oils are desired. Also, the presence of linoleic acid in the oils indicate that they may be suitable as supplements for lowering the LDL cholesterol levels of the body as well as serve, via Gamma Linolenic Acid, in the biosynthesis of the very important anti – inflammatory 1 – series prostaglandins

Effects of temperature in relation to sheet metal stamping

The demand to reduce the use of lubricants and increase tool life in sheet metal stamping has resulted in increased research on the sliding contact between the tool and the sheet materials. Unlubricated sliding wear tests for soft carbon steel sliding on D2 tool steel were performed using a pin-on-disk tribometer. The results revealed that temperature has an influencing role in the wear of tool steel and that material transfer between tool and sheet can be minimized at a certain temperature range in sheet metal stamping

Heavy Metal Composition Of Commercial Fertilizers From Zaria, Northern Nigeria

The heavy metal composition of some commercial fertilizers and soil supplements used in Zaria were analysed. The fertilizers analysed include Liquid Organic fertilizer, Palette Organic fertilizer, Urea, Super phosphate, NPK, some of the soil supplements analysed are cow dung and chicken droppings. Using Atomic Absorption Spectrophotometer (AAS) the following range of heavy metal concentrations were obtained: Cu 3.92-38.14mg/l, Mn 0.057-199.17mg/l, Cr 0.19-2.207mg/l, Zn 1.35-83.12mg/l, Fe 5.00-514.18mg/l, Ni 0.063-149mg/l, Pb 9.86-15.52mg/l, Co 0.26-2.87mg/l..Super phosphate had the highest abundance of Iron (514.18mg/l). These values were compared to standards for heavy metals in fertilizers and supplements for other countries and were found to be below the limits. Like other countries, it will be important for Nigeria to have set standards for heavy metals levels for fertilizers used in the country