The SSST seems to be superior to the T25FW in terms of dynamic range, floor effect and discriminatory power. The SSST is a relevant alternative for the T25FW as the ambulation component of the MSFC.
In Europe, theoretical approaches to physical therapy and rehabilitation in multiple sclerosis often appear significantly different. While there is general agreement that rehabilitation plays an important role in maintaining and improving function in persons with multiple sclerosis, no consensus exists on what may be the most effective approach to achieve the best possible functionality within an individual's limitations.The objective of this paper is to initiate an analysis of currently applied physical interventions for people with multiple sclerosis throughout Europe during inpatient or outpatient rehabilitation programs. A study of the content of rehabilitation may show presently performed treatment methods revealing the basic considerations that nowadays guide clinicians implicitly or explicitly in the treatment of persons with multiple sclerosis. Following this first step, comparative studies can be set up.
Conformal antennas on aircraft allow the use of non-conventional antenna locations such as the skin of the aircraft. However, when antennas are installed at these locations they are subject to steady and unsteady aerodynamic loads. The inertial forces and these aerodynamic loads will cause deformations and vibrations of the total antenna surface. The effect of these distortions on antenna performance will be most significant on highly directional antennas. The aim of the present paper is to describe technology development for estimating the effects of surface distortion on antenna performance. The technology is applied to a Side-Looking Airborne Radar (SLAR) antenna on a reconnaissance pod mounted on a fighter type aircraft. This generic SLAR antenna is a phased array antenna covering two faces of the pod: one part on the vertical side face and one part on the lower face of the pod. Radiation patterns are computed for distorted antenna surfaces. The computational model for the determination of the disturbed radiation pattern is based on geometrical parameterisation of the Stratton-Chu integral equations.
Purpose
Insight in the temperature distribution on the internal and external surface of the nacelle is of great importance during the design phase of an aircraft. However, detailed information is not always needed. In a preliminary project stage or during parametric optimization, short analysis times are often more crucial than high accuracy. In such cases, the global insight in the temperature levels suffices to gain understanding of the relevance and influence of certain parameters. Nevertheless, estimating the maximum temperature for the most adverse conditions should also be done before a prototype is built. Therefore, this study aims to present and compare a simplified and an advanced methodology for the analysis of engine bay cooling and ventilation systems as well as heat transfer in the nacelle in a small airplane equipped with a turboprop engine in the tractor arrangement.
Design/methodology/approach
Both approaches included conductive, convective and radiative heat transfer in the engine bay of the small airplane I-23 as well as heat conduction in the nacelle made of material with anisotropic thermal conductivity. The one-dimensional (1D) model assumed that the nacelle with the air flow and engine was represented by a lumped thermal model in which heat was exchanged between the different lumped segments (the nodes) and the flowing air and engine. The three-dimensional (3D) model was based on the continuous control volume approach for heat, fluid flow and thermal radiation as well as on realizable k-ε turbulence model. Both models used commercial software.
Findings
The temperature distribution at the internal and external surface of the top nacelle was calculated. The 1D model predicted a temperature per node (per segment) while the 3D model was able to determine its values accurately and find the location of hot spots. Considering the complex geometry of the engine bay and nacelle and the assumed simplification, the obtained 1D and 3D results agreed quite well.
Practical implications
Both models will help in the development of new ventilation and cooling systems of the engine bay and nacelle as well as in the selection of materials for parts of the top cowling in the newly redesigned airplane I-23 equipped with a turboprop engine. In addition, the methodology presented in this paper might be applied in the development of other airplanes.
Originality/value
The 1D and 3D models of complex heat transfer inside the engine bay and in the nacelle of the newly re-designed airplane I-23 were elaborated and compared.
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