Surface Tolerances for Aircraft Design, Maintenance and Repair

飞行器表面的气动设计受到许多约束，并且在设计周期中交互地被细化。其中一个约束是接头处的制造公差、表面粗糙度/波纹度和间隙。在设计阶段，空气动力学部门设定可接受的公差，以尽量减少它们对性能和燃料燃烧的影响。目前的方法只估计多余的阻力，并根据解释的结果，从表面discountinities放置在零压力梯度。因此，这些方法不考虑升力和俯仰力矩的影响。该项目将开发和验证基于CFD的快速工具，这些工具可以在广泛的表面形状和流动条件下捕获这些影响，从而获得更准确的数据表方法。这些方法将使设计师能够在性能优势和制造成本之间权衡表面光洁度要求，从而降低总拥有成本。此外，该项目的结果将为运营商提供信息，以帮助他们减少因飞机老化而增加的燃油消耗。

The aerodynamic design of aircraft surfaces is subject to many constraints and is refined interactively during the design cycle. One of the constraints is the manufacturing tolerance at joints, surface roughness/waviness and gaps. During the design phase acceptable tolerances are set by the aerodynamic department to minimize their effect on performance and fuel burn. The current methods only estimate the excrescence drag and are based on the interpretation of results from surface discountinities placed in a zero pressure gradient. Therefore these methods do not consider effects on lift and pitching moment. This project will develop and validate rapid CFD-based tools that capture these effects over a wide range of surface shapes and flow conditions, and consequently more accurate data sheet methods. These methods will enable the designer to trade surface-finish requirements between performance benefits and manufacturing costs and thus reduce total-ownership costs. In addition the results from this project will be tailored to provide information to operators to assist in their maintainance in order to minimise the increase in fuel burn due to ageing aircraft.