Why are there not many 90 duct machines?

Why are there not many 90 duct machines?

In the aviation field, bypass ratio (BPR) is one of the important indicators to measure the performance of turbofan engines. In recent years, high bypass ratio engines (such as BPR>10) have become the mainstream of civil aviation, but engines with a 90 bypass ratio are extremely rare. This article will analyze this phenomenon from multiple dimensions such as technology, economy, and market, and explore the reasons behind it based on the hot topics and hot content on the entire network in the past 10 days.

1. Technical challenges of 90 duct machine

The design of high-bypass-ratio engines is not a simple enlargement, but involves complex aerodynamics, material science, and manufacturing processes. The following are the main technical problems faced by the 90 duct machine:

2. Economic and market demand analysis

From a business perspective, the cost-performance curve of a 90 bypass ratio engine shows diminishing marginal benefits. The following is relevant market data on hot topics in the aviation field in the past 10 days:

Data shows that when the bypass ratio is increased from 10 to 90, the increase in fuel efficiency is limited, but R&D costs increase exponentially. This is in conflict with the recently hotly discussed topic of "carbon neutrality in the aviation industry" - although the industry is pursuing more environmentally friendly engines, the input-output ratio of ultra-high bypass ratios is not optimistic.

3. Competition among alternative technology paths

According to recent trends in the aerospace field, the industry is more inclined to develop breakthrough technologies such as hybrid power and hydrogen energy, rather than simply pursuing the limit of bypass ratio. Here’s a comparison of popular alternatives:

4. Airworthiness Certification and Operational Restrictions

Airworthiness certification is another key factor restricting the development of 90 ducted machines. In recent discussions between the FAA and EASA on new engines, the following issues have been focused on:

1.Airport compatibility:90 ducted aircraft may need to modify the runway and parking spaces
2.Maintenance system: Existing ground handling equipment cannot support ultra-large engines
3.Safety redundancy: Control problems in case of single engine failure

5. Conclusion: Incremental innovation is better than extreme breakthrough

Taking into account technical, economic and market factors, the aviation industry is more inclined to choose an optimization solution with a bypass ratio between 10 and 15, rather than directly developing a 90-passenger aircraft. This echoes the recently hot debate on "disruptive innovation versus incremental improvement" - in the field of aero-engines, reliability, economy and incremental improvements are often more important than parameter breakthroughs.

In the next ten years, with the development of new materials (such as metal matrix composites) and new layouts (such as open rotors), the bypass ratio may gradually increase, but the possibility of directly jumping to 90:1 is extremely low. Industry resources will be invested more in more practical directions such as hybrid power and sustainable aviation fuel.