Preliminary Design Assessments of Pusher Geared Counter-Rotating Open Rotors: Part II — Impact of Low Pressure System Design on Mission Fuel Burn, Certification Noise and Emissions
Preliminary Design Assessments of Pusher Geared Counter-Rotating Open Rotors: Part II — Impact of Low Pressure System Design on Mission Fuel Burn, Certification Noise and Emissions
复制标题
推进器齿轮反转开式转子的初步设计评估：第二部分 — 低压系统设计对任务燃油燃烧、认证噪音和排放的影响
DOI：
10.1115/gt2015-43816
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
V. Sethi
中科院分区：
文献类型：
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作者：
Pablo Bellocq;I. Garmendia;V. Sethi
在这本由两部分组成的出版物中，介绍了一架160 PAX中程飞机的对转齿轮开放式转子(GOR)的主要低压系统参数对任务燃料燃烧、认证噪声和排放的影响。由于GOR具有高推进效率，相对于传统的高旁路比涡轮风扇，GOR具有显著降低燃油消耗和排放的潜力。然而，这种新的发动机结构在发动机和飞机层面都提出了许多设计和运行方面的挑战。在初步设计阶段，有必要评估GOR的主要低压初步设计参数对任务燃料燃烧、认证噪声和排放的影响，以确定最佳设计区域。当由于设计、操作或法规限制而需要进行折衷时，这些评估也可能有助于开发过程。这份由两部分组成的出版物的第一部分描述了GOR的主要低压(LP)系统设计选择，以及为评估开发的初步设计哲学和模拟框架。第二部分介绍了评估研究。固定参照物飞机和任务被用来评估不同的GOR发动机设计。结果以一维或二维曲线图的形式呈现，其中一个或两个设计参数同时变化。由于评估使用了初步设计工具，特派团燃料消耗、认证噪音和排放量的变化表现为相对于基线设计的差异。研究的主要结论是：·增加螺旋桨间距(从0.65米增加到1.3米)以相对较小的燃料燃烧惩罚(∼0.3-0.5%)显著降低噪声(每个认证点有6个∼)·与未修剪的设计相比，20%修剪的CRP将立交桥噪声降低至少2.5EPNdB，接近噪声至少降低4.5EPNdB。相应的燃料燃烧惩罚为∼2%。·可以通过增加CRP的直径和适当控制CRP的转速来减少侧线和立交桥噪声。可以通过减小螺旋桨的直径或转速来降低进场噪声。·无论剪切与否，降低后螺旋桨相对于前螺旋桨的转速都会降低噪声，并且在一定程度上还会降低任务燃料的消耗。进一步降低转速将对燃料燃烧产生不利影响。·对于给定的螺旋桨转速，变速箱的扭矩比固定在±3%以内。版权所有©2015，ASME
In this 2-part publication, the impact of the main low pressure system parameters of a counter rotating Geared Open Rotor (GOR) on mission fuel burn, certification noise and emissions is presented for a 160 PAX medium haul class aircraft.Due to their high propulsive efficiency, GORs have the potential to significantly reduce fuel consumption and emissions relative to conventional high bypass ratio turbofans. However, this novel engine architecture presents many design and operational challenges both at engine and aircraft level.The assessment of the impact of the main low pressure preliminary design parameters of GORs on mission fuel burn, certification noise and emissions is necessary at preliminary design stages in order to identify optimum design regions. These assessments may also aid the development process when compromises need to be performed as a consequence of design, operational or regulatory constraints.Part I of this two-part publication describes the main low pressure (LP) system design choices for a GOR as well as the preliminary design philosophy and simulation framework developed for the assessments. Part II presents the assessment studies. A fixed reference aircraft and mission were used to evaluate the different GOR engine designs. The results are presented in the form of 1-D or 2-D plots in which one or two design parameters are varied at the same time. The changes in mission fuel burn, certification noise and emissions are expressed as differences relative to a baseline design, due to the fact that preliminary design tools were used for the assessments. The main conclusions of the study are:• Increasing spacing between the propellers (from 0.65 to 1.3m) reduces noise significantly (∼6 EPNdB for each certification point) with a relatively small fuel burn penalty (∼0.3–0.5%)• Relative to unclipped designs, 20% clipped CRPs reduce flyover noise by at least 2.5 EPNdB and approach noise by at least 4.5 EPNdB. The corresponding fuel burn penalty is ∼2%.• Sideline and flyover noise can be reduced by increasing the diameter of the CRP and appropriately controlling CRP rotational speeds. Approach noise can be reduced by either reducing the diameters or the rotational speeds of the propellers.• Regardless of clipping, reducing the rotational speed of the rear propeller relative to the forward propeller reduces noise and, to a certain limit, also mission fuel burn. Further reductions in rotational speed would have an adverse effect on fuel burn.• For given rotational speeds of the propellers, the torque ratio of the gearbox is fixed within ±3%.Copyright © 2015 by ASME