No abstract

The incident of unmanned aerial vehicles (UAVs) incursion into aerodrome often happens due to the popularity of drones among amateurs, and this may lead to a threat to the safety of commercial aircraft operation. Hence, it is essential to estimate the damage level of commercial aircraft caused by drone strikes. From the data analysis of bird strike accidents over the period 1990-2019, it is found that the engine part is more susceptible to be damaged by bird strikes compared to the other aircraft parts. In this paper, the damage of engine fan blades caused by the drone ingestion is simulated by using a drone (MAVIC Pro) impinging onto a typical business engine (CFM56-5B) with the aid of FEM (finite element method). It is demonstrated that the collision position and collision posture both would affect the damage level of engine fan blades significantly. More damage to fan blades can be detected for the 75% collision position, and the complex collision posture would lead to much larger damage on the engine fan blades. The results presented in this work can be used to guide the decision made on the drone incursion incidents over the aerodrome.

This paper is devoted to investigating the influence of UAVs airborne collision with civil aircraft engine on the operation safety of commercial aircraft. The damage levels of the civil aircraft fan blades and compressor blades during the UAVs airborne collision are both evaluated based on the Finite Element Method (FEM) simulation. Besides, the percentage of the engine thrust loss can be estimated by the reduction of pressure ratio throughout the engine using Computational Fluid Dynamics (CFD) simulation. In our study, it is found that UAVs ingestion at approach flight phase has the highest UAVs debris weight of 80g which can cause most severe damage to aircraft Inlet Guide Vane (IGV) Low Pressure Compressor (LPC) blades. This thrust loss can reach up to 75% when the damage of High Pressure Compressor (HPC) blades is included in the analysis. More simulations are will be carefully carried out to check the reliability of this conclusion, in which the influence of secondary level of damage especially IGV blades debris impact on HPC blades are considered.

Crash area estimation for ground risk of small unmanned aerial vehicles due to propulsion system failures

The drone weight less than 250g is often treated as a 'harmless' category by many authorities such as EASA (European Aviation Safety Agency) and CAAS (Civil Aviation Authority of Singapore). Is this small drone really safe and does not affect the operation of commercial aircraft? This paper is devoted to presenting a Finite Element Method (FEM) simulation method to analyze the performance of the commercial aircraft engine under the collision of the harmless categorized drone with a weight of 250g. The damage levels of the fan blades and compressor blades during the drone collision process are both investigated. Besides, another type of drone with a much higher weight (750g) is also analyzed to give a comparison study. The result shows no apparent damage to the aircraft engine fan blades, IGV, and LPC blades for the drone of MAVIC MINI, while some damage can be detected for the engine fan blades under the impact of the drone of MAVIC Pro.

Collision severity evaluation of generalized unmanned aerial vehicles (UAVs) impacting on aircraft engines.

Damage severity prediction of helicopter windshields caused by a collision with a small unmanned aerial vehicle (sUAV) Mohd Hasrizam Che Man; Low, Kin Huat 2021 Mohd Hasrizam Che Man & Low, K. H. ( 2021). Damage severity prediction of helicopter windshields caused by a collision with a small unmanned aerial vehicle (sUAV). AIAA

Industrial boilers by using biomass for electricity generation have received significant attention recent years. However, during the process, a significant fraction of thermal energy is often lost to the environment as flue gas. The exhaust flue gas heat loss which ranges from 150-180°C (423.15-453.15K) has led to discovery of importance of recovering the waste heat of the flue gas to overcome the reliance on fossil fuel. Stirling engine as an external combustion engine with high efficiencies and able to use any types of heat source is the best candidate to recover waste heat of the exhausted gas by converting it into power. Thus, in this study Stirling engine was introduced in order to evaluate the possibility of recovering waste heat from industrial boilers to produce power. For this reason, Computational Fluid Dynamic (CFD) simulation test was performed to design an initial computational model of Stirling engine for low temperature heat waste recovery. The CFD model was validated with the experiment model and shows 4.3% of deviation. The validated model then connected to a lower temperature. It shows that when the heat source is 400K, the work done by the engine is 8.4J compared to when heat source 773K the work done is 17.0 J. The computational model can be used to evaluate the performance of Stirling engine as waste heat recovery of biomass-based industrial boilers for low-grade temperature heat source.