A Review of the Current Regulatory Framework for Supersonic Civil Aircraft: Noise and Emissions Regulations

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Over the past two decades, there has been a renewed interest in the development of a new generation of supersonic aircraft for civil purposes that could potentially succeed Concorde. However, the noise annoyance is still considered one of the hampering factors to meet public consensus. This paper aims at revealing the potential of numerical simulations to predict sonic boom signature in Near Field at early design stages. In particular, the paper further demonstrates the applicability of the numerical approach proposed by NASA and other partners during the Sonic Boom Prediction Workshops held between 2014 and 2021, to compute the pressure signature of aircraft in the zone close to it. The results highlight the suitability of the approach (1) to capture the impact of aircraft flight condition variations on the sonic boom signature, (2) to enable the characterization of novel aircraft layout, including Mach 5 waverider configuration, (3) to provide near-field shock wave noise predictions that can be used to evaluate shock propagation, on-ground signature analyses, and annoyance assessment.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evaluation of Sonic Boom Shock Wave Generation with CFD Methods

Graziani,

Petrosino,

Jäschke

et al. 2024

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Experimental Investigation of Particulate Number Measurement Methodology for Micro-Turbojet Engine Emissions

Xu,

Wang,

et al. 2024

Increasing aviation activities have heightened concerns about particulate emissions from aircraft engines. Current ICAO standards mainly focus on large civil turbofan engines, leaving a gap in the research on PN emissions from small aircraft engines. This study examined the PN emission characteristics of micro-turbojet engines, including the morphology, PN, and size distribution under different load conditions, compared with a micro-piston engine. The results showed that the nvPM from micro-turbojet engines was larger and more complex than typical aviation soot, likely due to reduced combustion efficiency and incomplete fuel combustion. Micro-turbojet engines exhibited fewer fluctuations in their emission index number (EIn) and emission index mass (EIm) at lower speeds. The geometric mean diameter (GMD) of particles was inversely correlated with thrust, while the geometric standard deviation (GSD) slightly increased with thrust. Quantitative comparisons indicated that PN emissions from micro-turbojet engines were higher, with EIn values ranging from 2.0 to 3.3 × 1016/kg fuel compared with 1.2 to 1.5 × 1016/kg fuel for micro-piston engines. EIm values for micro-turbojet engines ranged from 8 to 40 mg/kg fuel, while micro-piston engines had slightly higher values due to better carbonization. These findings validated the measurement methodology used to accurately assess PN emissions under low-thrust conditions in micro-turbojet engines. These results provide crucial insights and support for the future monitoring and regulation of PN emissions across all thrust conditions in small aircraft engines.

A Systematic Approach towards the Integration of Initial Airworthiness Regulatory Requirements in Remotely Piloted Aircraft System Conceptual Design Methodologies

Gómez-Rodríguez,

Turkoglu,

Cuerno-Rejado

2024

The regulatory framework of Remotely Piloted Aircraft Systems (RPASs) has recently experienced an extraordinary evolution. This article seeks to improve the integration of certification considerations in RPAS conceptual design approaches so as to enhance the safety, certifiability and competitiveness of their resulting designs. The first part of the research conducts a two-stage analysis of contemporary regulations related to an RPAS’s initial airworthiness. In the first stage, the broad international regulation paradigm is evaluated attending to a set of criteria that are tightly related to both airworthiness and design considerations. The second stage keeps the most promising documents from a design–integration standpoint, which are assessed according to their applicability considering both design and operational aspects. The results of this analysis provide insights regarding the main issues in airworthiness design criteria extraction and integration in design methodologies. To aid the designer in surmounting these challenges, a flexible procedure named DECEX is developed. Considering the documents and findings from the survey, and attending to the scope of the design methodology being developed, it aids in establishing a complete regulatory document corpus and in comparing and extracting the applicable airworthiness design criteria. Two case studies for different RPAS types are conducted to demonstrate its application.