: Evaluation of Turboelectric Propulsion for Commercial Transport You are advise

: Evaluation of Turboelectric Propulsion for Commercial Transport
You are advised to spend no more than six hours on this task.
Produce and upload a set of presentation slides with pre-recorded audio commentary
justifying and summarising your assessment of the potential for deployment of
Turboelectric Propulsion in the successor to the New Efficient Aircraft, with a launch
target of 2030. The presentation should contain no more than 10 slides and the audio
recording should not exceed 8 minutes. The presentation should not contain video.
[40 marks]
Approach
The required format for the presentation and suggested reading and analysis that will support
your assessment are set out below.
The majority of marks are available for how you use technical evidence to justify your
assessment of the technology in the presentation and you should focus your efforts accordingly.
Since this is an open-ended task without a unique right answer, you are advised to limit the time
you spend on it, as you would in a professional role, and spend no more than 6 hours including
analysis and background research. This might be split into two hours reviewing the
recommended reading, two hours of analysis, and two hours preparing and recording the
presentation.
Format
Good slides are visual, can be understood rapidly. They should not be text-heavy. Use of
annotated images and plots to support your argument can be particularly effective.
Where you refer to results of your own calculations you should attach evidence of these
calculations as an appendix so as not to spoil the flow of the presentation. The appendix does
not need to be typeset or written formally, but should provide a logical and legible record of the
evidence on which you base your assessment. If you provide an appendix, it should be added at
the end of the presentation (the appendix is not included in the 10 slide limit)
You may use images, data and quotations from other studies in your presentation, but these
must be accompanied by references to their primary source.
5
You must submit the presentation as a power point file (.pptx). Please consult the Module
Coordinator if you are not able to work in this format to discuss alternative arrangements. Please
name the file in the format ‘Surname_Initials_StudentNumber.pptx’, for example
Richardson_ES_3248994.pptx
Do not include video recordings in your presentation.
Suggested reading
The following articles are recommended background reading for this Task. Both articles are from
the same research group at NASA Glenn. Reference [1] from 2008 is less current but provides a
simpler overview and gives useful data that compares a conventional turbofan arrangement
against superconducting-turboelectric systems directly. Reference [2] from 2016 provides a more
advanced analysis of the same aircraft propulsion concept. Both articles can be downloaded
from the Assignment 1 folder on Blackboard for use in this Task.
[1] Kim, H.D., Brown, G.V. and Felder, J.L., 2008. Distributed turboelectric propulsion for
hybrid wing body aircraft.
[2] Welstead, J. and Felder, J.L., 2016. Conceptual design of a single-aisle turboelectric
commercial transport with fuselage boundary layer ingestion. In 54th AIAA Aerospace
Sciences Meeting (p. 1027).
You may wish to explore other engineering literature on the topic further.
Suggested discussion:
i. The effective bypass ratio of a turboelectric propulsion system can be defined as the total
mass flow rate through the fans divided by the total mass flow rate through the cores of
the gas turbine engines. You should discuss how you would select the effective bypass
ratio for the turboelectric propulsion system. In doing so, you may find it helpful to review
the discussion about choice of turbofan bypass ratio in Chapter 7 of the Course Book.
ii. For a given effective bypass ratio there is also a choice of the number of fans to be used.
You should discuss the rationale for using more or fewer fans. You might consider how
the total weight and efficiency of the fans and associated motors and ducting varies as
you change the number of fans. The variation of turbomachinery weight with diameter is
discussed in a basic way in Section 7.7 of the Course Book.
iii. References [1] and [2] consider concepts with a high level of integration between the
airframe and the propulsion system – particularly by positioning the fans so that they
ingest the wing boundary layer and contribute to high lift for short take off capability. You
should consider whether the turboelectric propulsion concept would still be beneficial
even within a conventional tube and wing aircraft architecture with podded fans. You
might consider how the nacelle drag is affected by the number and size of fan pods, and
how it contributes to the overall propulsive performance. Nacelle drag is discussed in
Section 7.6 of the Course Book.
iv. The weight of the turboelectric propulsion system is affected by the need for high power
electric generators and motors. References [1] and [2] consider use of high power
density superconducting electric machines (data for the power density of this type of
machine can be deduced from Table 3 of Reference [1]). Note that high power density
non-superconducting permanent magnet electric generators and motors have a power
density on the order of 6 kW/kg, discuss whether turboelectric propulsion is likely to be
advantageous using current commercially-available electric machines, or whether
development of superconducting electric drives are necessary in order to make
turboelectric propulsion viable for the successor to the New Efficient Aircraft. You could
assess the effect of system weight on the corrected sfc following an approach similar to
Section 7.7 of the Course Book.
Load the GasTurb13 software, select ‘Geared Turbofan A’ from the ‘Jet Engines’ tab and then
the ‘Performance’ option under the ‘Engine Design’ tab. Load the DemoGearedTurbofan.CYG
engine data and run a Design Point calculation for the default engine data provided. This
engine set up is a plausible design for a practical geared turbofan engine.
Note that the main input parameters (other than outer fan pressure ratio and the presence of
various cooling flows) are approximately the same as in Tables 1-2. Examine the output of the
GasTurb13 calculation and explain the reasons for the main differences between the
GasTurb13 results and the results from your hand calculation in Task 1a. You may perform
and refer to any additional calculations that help to quantify and explain the reasons for the
differences.
Your answer should not exceed 300 words of text.