Compressible flow and Propulsion Systems
ME-417
Complex Engineering Problem [CLO-3}
1. Problem Statement
The aviation industry faces a growing need to balance increased performance demands with a
reduced environmental footprint. Students have to analyze the gas power shaft engines along with
their environmental impacts. Hence, you are tasked with comparing and analyzing the performance
and emissions of three different engine configurations within the context of a short-haul regional
aircraft.
i. Conventional Turbofan Engine: A baseline high-bypass ratio turbofan representing current
technology.
ii. Geared Turbofan Engine: A similar high-bypass ratio turbofan but incorporating a gearbox
between the fan and low-pressure turbine, allowing for more optimized component speeds.
iii. Open Rotor Engine: An advanced concept featuring unducted, counter-rotating propellers
driven by a gas turbine core.
2. Constraints/Assumptions:
i.
Use realistic assumptions and data (e.g., aircraft size, mission profile, engine
specifications). You can find reliable sources from aerospace publications, manufacturer
websites, and academic papers.
ii.
Employ appropriate software tools or programming for thermodynamic calculations and
data visualization if desired. You may use EES, MATLAB, Python, or any other software
for analysis.
iii.
Focus on a short-haul regional jet with capacity for 70-100 passengers.
iv.
Consider a typical mission profile of approximately 1000 nautical miles with
corresponding cruise altitude and speed requirements.
v.
The open rotor concept is less mature; analyze it with possibilities for performance gains
through technology advancements, but acknowledge potential development risks.
vi.
Regional airports often have stricter noise regulations. Each engine configuration should
be evaluated against a specified noise limit at takeoff and landing. This might necessitate
design compromises. Use standards and regulations for the region you are analyzing e.g .
For U.S. noise standards, refer to the Code of Federal Regulations (CFR) Title 14 Part
36 – Noise Standards: Aircraft Type and Airworthiness Certification (14 CFR Part
36), or Federal Aviation Administration (FAA), DOT standards for Stages as per the
aircraft chosen, or International Civil Aviation Organization (ICAO) noise standards
or The Air Navigation (Aircraft Noise) Regulations 2018 by Government of Australia,
vii.
Prioritize the analysis of NOx emissions, as these are particularly harmful and a significant
regulatory focus in aviation.
viii.
Qualitative discussions of technology implications are as important as quantitative
analysis.
3. Computational/Modern Tool Usage
Students may use ‘EES’, ‘MATLAB’ or ‘Python’ for the numerical analysis.
4. Deliverables
• A technical report with calculations, system diagrams, plots, and clear explanations of
methodological choices containing the following:
i.
•
•
•
ii.
•
•
iii.
•
•
iv.
•
•
•
•
Thermodynamic Modeling:
Develop models for each engine configuration.
Calculate key performance parameters including thrust, specific fuel consumption (SFC),
and overall efficiency at typical cruise conditions.
Verify the above analysis on a software from the list for each type of Gas Turbine engines.
Emissions Analysis:
Investigate primary pollutants from gas turbine engines (NOx, CO, unburnt hydrocarbons,
particulates).
Estimate the emission levels for each engine type, considering factors like operating
conditions and combustor design choices.
Environmental Impact Assessment:
Quantify the noise impact of each engine configuration, especially critical for the open
rotor due to its unique design.
Discuss the potential effects of emissions on local air quality and contributions to global
climate change.
Design Trade-offs and Recommendations:
Analyze the performance/efficiency gains of each engine against the relative increases (or
decreases) in emissions and noise pollution.
Consider real-world constraints like aircraft integration, and certifications.
Provide a reasoned recommendation for which engine configuration might offer the best
compromise for short-haul regional aircraft in the near future, justifying your selection.
The emphasis is on the analytical process and trade-off considerations rather than having a
subjective solution.
Criteria
Excellent (5)
Good (4)
Average (3)
Below Average
(2)
Poor (1)
Data
Gathering
Student
effectively
collected all the
data that are
necessary to
solve the
problem.
Student has
collected 90% of
the data to solve
the problem.
Student has
collected 6080% of the data
to solve the
problem
Student has
collected 50% of
the data to solve
the problem.
Student has not
collected the
enough data to
solve the
problem.
Student
Student
Student
Student
Student
demonstrated a
demonstrated a
demonstrated a
demonstrated
demonstrated a
limited technical
good technical
basic technical
minimal or no
strong technical
understanding of
understanding of understanding of
technical
understanding of
thermodynamics,
thermodynamics, thermodynamics,
understanding of
thermodynamics,
IC Engines and
Technical
IC Engines and
IC Engines and
thermodynamics,
IC Engines and
Fluid
Knowledge
Fluid
Fluid
IC Engines and
Fluid
Mechanics, and
and
Mechanics, and
Mechanics, and
Fluid
Mechanics, and
may have
Understanding
was able to
may have
Mechanics, and
was able to
struggled to
apply this
struggled to
was unable to
apply this
apply this
knowledge to
apply this
apply this
knowledge to
knowledge to
solve most
knowledge to
knowledge to
solve the
solve most
aspects of the
solve all aspects
solve the
problem.
aspects of the
problem.
of the problem.
problem.
problem.
Sustainable
solution to
address the
issue
Student has
provided a
realistic solution
and easy to
apply.
Student has
provided a
realistic solution
but has few
difficulties to
apply.
Student has
provided a
realistic solution
but has many
difficulties to
apply.
Student has
provided a
realistic solution
but can’t be
apply.
No solution is
provided.
Timely
Submission
Assignment
submitted within
due date.
--
--
--
Assignment not
submitted within
due date.
Marks Obtained = _________
Teacher Signature: ______________
Complex Engineering Problems Attributes
S.no
1
2
3
4
Attributes
Preamble
Range of
Conflicting
Requirements
Depth of Analysis
Required
The extent of
stakeholders and
level of conflicting
requirement
Consequences
This problem requires in-depth engineering knowledge of
Thermodynamics and Internal combustion Engines.
This problem is addressing environmental impact and fuel efficiency.
This problem has no obvious solution as every aircraft uses a
different type of engine. Also, the amount of CO2 absorbed by the
tree is not constant. The sustainable solution for every student will be
different.
This problem is related to two stakeholders as Emissions are
generated by the Aviation industry (Ministry of Aviation) and this is a
problem for the Ministry of Environment.
The problem has significant consequences in terms of the
environmental impact of aircraft emissions and the need to find
sustainable solutions.