The Effects of Tail-Tilt on the Yaw Stability of Baseline-V Blended Wing Body Aircraft / Nur Syazwani C.M and Rizal E.M. Nasir

This paper presents a study on the effects of tilting the tail on yaw stability performance of Baseline-V blended wing body (BWB) aircraft. The study on BWB aircraft began in UiTM in 2005 and a few designs of BWB aircraft have been studied and published. Recent progress on BWB study in UiTM indicates major flaws in BWB technology particularly its stability and issues regarding limited controllability since it is unequipped with any vertical tail to perform directional motion. Some ideas have been proposed generally to overcome the problems such as designing large central elevator on Baseline-I, attaching canard and belly-flap on Baseline-II, general shape mimics flying birds for Baseline-III and birds inspired control surface by adding horizontal tail for Baseline-IV. The results showed that some of the ideas gave positive feedback into stability and some degraded the aerodynamic efficiency. Even to this day, in general the research community and industry have not concluded any solutions or guidelines to overcome some problems of BWB aircraft design. It is proposed that the Baseline-V BWB aircraft to have a horizontal close-coupled tail located at wing trailing edge inspired by bird control surface so that longitudinal (pitch) and lateral-directional (yaw) stability suffered by BWB aircraft are solved. The objective of this study was to determine the effectiveness of close-coupled tail on Baseline-V BWB to overcome the problems regarding stability. This was achieved by conducting wind tunnel tests at low speed tunnels at Universiti Teknologi Malaysia (UTM-LST). The test model was a full scale model of Baseline-V and was tested at actual test speed of 15m/s (54 km/h). The longitudinal and lateral directional aerodynamic characteristics of the aircraft such as coefficients of forces (lift, drag and side forces) and coefficients of moments (roll, pitch and yaw moment) were experimentally measured. Based on the results, tilting tail of Baseline-V gave positive feedback in terms of stability. The Effects of Tail-Tilt on the Yaw Stability of Wing Body Aircraf

The Effect of Elevons Deflection to Aerodynamic Coefficients of A Tail-less Blended Wing-Body Planform / Rizal E. M. Nasir ...[et al.]

Control surfaces play a big role in stabilizing and maneuvering an aircraft. This paper investigates the effect of control surface allocations, specifically deflection of four elevons on a BWB planform, on aerodynamic coefficients. Elevon allocations can be in a form of single-elevon deflection, two-elevon deflection in unison or in opposite deflection angles and four-elevon deflections in unison or in opposite deflection angles. Six aerodynamic coefficients which represent three forces and three moments in three axes are measured via wind tunnel experiment at 25 m/s. The wind tunnel model is of a flat, thin plate with planform similar to a typical stealth, flying-wing aircraft. Thirty-one (31) cases of different elevon deflections are tested at a fixed pitch angle of attack and zero angle of sideslip. The results shows that significant changes in drag, sideforce and lift forces are observed at almost all elevon deflection cases. The roll moment and pitch moment change with respect to elevon angle depends on the number of elevons utilized while yaw moment is not much affected by elevon deflections except for some cases

Wind Tunnel Tests of UiTM Blended Wing Body - Unmanned Aerial Vehicle (BWB-UAV) Prototype / Wirachman Wisnoe ...[et al.]

In 2014 Universiti Teknologi MARA (UiTM) Malaysia has been granted a research project under Prototype Research Grant Scheme from the Ministry of Higher Education Malaysia to build a prototype of Blended Wing Body - Unmanned Aerial Vehicle for aerial surveillance. In this paper the aerodynamic characteristics of the prototype in the longitudinal direction are presented in terms of lift coefficient, drag coefficient, and pitching moment coefficient obtained from wind tunnel tests. The tests are conducted on a ¼ scaled half model aircraft placed in UiTM Low Speed Tunnel at wind speed of 20 m/s, 25 m/s, 30 m/s, 35 m/s and 40 m/s representing Reynolds number in the order of 105. For each wind speed, the angle of attack is varied from -10º to 64º to observe the full capability of the aircraft. Visualisation using thread tufts is also executed to see the flow pattern on the surface of the aircraft at certain angles. The results show that the maximum lift coefficient is around 0.65 at 28º angle of attack, the minimum drag coefficient is below 0.03 at zero angle of attack, and the maximum lift-to-drag ratio is about 20 at 3º angle of attack. The pitching moment curve indicates a static stability with negative slope between -7º to 10º angle of attack. Visualisation shows the flow separation progress on the surface of canard, wing and fuselage

Blended Wing-Body Unmanned Aerial Transport Aircraft: A conceptual design

UAVs have advantages in assisting works such as aerial  surveillance,  agriculture  and transport with  minimal  risk,  low  operating costs,  relatively  inexpensive  price  and  ability  to  automate  the  work.  Currently the UAV technology is expanding to include unconventional   designs   and configurations   to suit to their purposes. Blended Wing-Body (BWB) technology   promises   high aerodynamic efficiency that translates to better flight performance over conventional fixed wing, multirotor and helicopter-type UAVs. Previous research has characterized flight behavior of a Blended Wing-Body UAV  stabilized  by  four  elevons.  The study leads to optimization of BWB UAV design that ensured positive stability and good controllability. While many courier companies are focusing on the short-range, last-mile delivery using multirotor drones,  the  transportation of  parcels  between  cities  is  still  by  land  vehicles susceptible to traffic congestion, floods and other natural disasters. Fixed-wing UAV is preferred for such transportation in Africa and no such service is offered in Malaysia. The popular multirotor transport drone proposed by courier companies in Malaysia is limited to short range delivery within a city. This paper introduces a conceptual design of a parcel transport UAV called Baseline-X BWB that carries two kilograms of payload for inter-city transport. The conceptual design scope of discussion is limited to aerodynamic estimation, flight performance and monetary cost. The advantages of this prototype over other UAVs are its longer range per battery capacity, larger and heavier payload capacity, and lower operating cost per mile and fleet cost per route than conventional design of the same size making it feasible and profitable for operators. Keywords: Air Transport; Blended Wing-Body; Unmanned Aerial Vehicle eISSN: 2398-4287© 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DO

Reviewing the world's edible mushroom species: A new evidence‐based classification system

Wild mushrooms are a vital source of income and nutrition for many poor communities and of value to recreational foragers. Literature relating to the edibility of mushroom species continues to expand, driven by an increasing demand for wild mushrooms, a wider interest in foraging, and the study of traditional foods. Although numerous case reports have been published on edible mushrooms, doubt and confusion persist regarding which species are safe and suitable to consume. Case reports often differ, and the evidence supporting the stated properties of mushrooms can be incomplete or ambiguous. The need for greater clarity on edible species is further underlined by increases in mushroom-related poisonings. We propose a system for categorizing mushroom species and assigning a final edibility status. Using this system, we reviewed 2,786 mushroom species from 99 countries, accessing 9,783 case reports, from over 1,100 sources. We identified 2,189 edible species, of which 2,006 can be consumed safely, and a further 183 species which required some form of pretreatment prior to safe consumption or were associated with allergic reactions by some. We identified 471 species of uncertain edibility because of missing or incomplete evidence of consumption, and 76 unconfirmed species because of unresolved, differing opinions on edibility and toxicity. This is the most comprehensive list of edible mushrooms available to date, demonstrating the huge number of mushrooms species consumed. Our review highlights the need for further information on uncertain and clash species, and the need to present evidence in a clear, unambiguous, and consistent manner