Cees Bil

Bio: Cees Bil is an academic researcher from RMIT University. The author has contributed to research in topics: Propulsion & Airfoil. The author has an hindex of 14, co-authored 146 publications receiving 942 citations.

Wing morphing control with shape memory alloy actuators

Abstract: Aircraft morphing is referred to as the ability for an aircraft to change its geometry in flight. Formally, flaps, spoilers, and control devices are considered morphing, but in general, morphing in aerospace is associated with geometrical changes using smart materials such as shape memory alloys. Shape memory alloy is a material that changes shape under heating and produces force and deflections, which make it potential actuator for a wing morphing system. The motivation behind this study is the application to small-sized and medium-sized unmanned air vehicles and the potential to increase range or endurance for a given fuel load through improved lift-to-drag ratio. The camber line of an airfoil section, the predominant parameter affecting lift and drag, is changed by resistive heating of a shape memory alloy actuator and cooling in the surrounding air. Experiments were conducted under wind tunnel conditions to verify analysis and to investigate the effects of its application on the aerodynamic behavior o...

Transdisciplinary systems engineering: Implications, challenges and research agenda

Abstract: Transdisciplinary processes have been the subject of research since several decades already. Transdisciplinary processes are aimed at solving ill-defined and socially relevant problems. Many researchers have studied transdisciplinary processes and have tried to understand the essentials of transdisciplinarity. Many engineering problems can be characterised as ill-defined and socially relevant, too. Although transdisciplinary engineering cannot widely be found in the literature yet, a transdisciplinary approach is deemed relevant for many engineering problems. With this paper we aim to present an overview of the literature on research into transdisciplinary processes and investigate the relevance of a transdisciplinary approach in engineering domains. After a brief description of past research on transdisciplinarity, implications for engineering research, engineering practice, and engineering education are identified. In all three areas, the current situation is described, while challenges are identified that still exist. The paper ends with a research agenda for transdisciplinary engineering.

Initial Sizing Methodology for Hybrid-Electric General Aviation Aircraft

Abstract: Electric and hybrid-electric propulsion offer unique possibilities to improve aircraft efficiency and performance. The potential advantages are fuel savings, lower emissions, and reduced noise. Bec...

Boundary Layer Theory

Abstract: The boundary layer equations for plane, incompressible, and steady flow are $$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

A Review of Morphing Aircraft

Abstract: Aircraft wings are a compromise that allows the aircraft to fly at a range of flight conditions, but the performance at each condition is sub-optimal. The ability of a wing surface to change its geometry during flight has interested researchers and designers over the years as this reduces the design compromises required. Morphing is the short form for metamorphose; however, there is neither an exact definition nor an agreement between the researchers about the type or the extent of the geometrical changes necessary to qualify an aircraft for the title ‘shape morphing.’ Geometrical parameters that can be affected by morphing solutions can be categorized into: planform alteration (span, sweep, and chord), out-of-plane transformation (twist, dihedral/gull, and span-wise bending), and airfoil adjustment (camber and thickness). Changing the wing shape or geometry is not new. Historically, morphing solutions always led to penalties in terms of cost, complexity, or weight, although in certain circumstances, thes...

Unmanned Aerial Vehicles: A Survey on Civil Applications and Key Research Challenges

Abstract: The use of unmanned aerial vehicles (UAVs) is growing rapidly across many civil application domains, including real-time monitoring, providing wireless coverage, remote sensing, search and rescue, delivery of goods, security and surveillance, precision agriculture, and civil infrastructure inspection. Smart UAVs are the next big revolution in the UAV technology promising to provide new opportunities in different applications, especially in civil infrastructure in terms of reduced risks and lower cost. Civil infrastructure is expected to dominate more than $45 Billion market value of UAV usage. In this paper, we present UAV civil applications and their challenges. We also discuss the current research trends and provide future insights for potential UAV uses. Furthermore, we present the key challenges for UAV civil applications, including charging challenges, collision avoidance and swarming challenges, and networking and security-related challenges. Based on our review of the recent literature, we discuss open research challenges and draw high-level insights on how these challenges might be approached.