DATE: 2018.11.28 This is a review of an article which introduces a new sensing method to characterize the convective wind activity on the surface of Mars TOPICS: • Introduction • Objective of the Study • Cited Studies • Setup • Mathematical Model • Experimental Backing • Results and Discussions • Conclusions • Suggestions

1. CONVECTIVE HEAT TRANSFER MEASUREMENTS
at the MARTIAN SURFACE
Erdi Çökelekoğlu
Samet Baykul
Metin Oktay Balaban
ME403 HVAC
Nov 28, 2018

3. Contents
• Introduction
• Objective of the Study
• Cited Studies
• Setup
• Mathematical Model
• Experimental Backing
• Results and Discussions
• Conclusions
• Suggestions

4. Introduction
• Over 50 years, exploration of Mars has been a strategic
research field.
• Important Mars missions in history
Year Spacecraft Operator Mission
1965 - 1971 Mariner NASA Flyby
1975 Viking NASA Lander
1996 Pathfinder NASA Lander
2003 Spirit and
Opportunity
NASA Rover
2011 Curiosity NASA Rover
2016 ExoMars ESA / Roscosmos Orbiter
Curiosity Self Portrait, 2018, Credits: NASA/JPL-Caltech

5. Objective of the Study - 1
• New sensing method to characterize the
convective wind activity on the surface of
Mars
• Since 2012, NASA uses REMS (Rover
Environmental Monitory System) for this
purpose. This instrument consist of
• WS: Wind Sensor
• GTS: Ground Temperature Sensor
• ATS: Air Temperature Sensors
• RHS: Relative Humidity Sensor
• UVS: Ultraviolet Sensor
• PS: Pressure Sensor

6. Objective of the Study - 2
• In 2020, ESA-Roscosmos will have a new Mars
mission namely ExoMars. This will be the first ESA
mission to land on Mars.
• The HABIT (HabitAbility) has been approved for
this mission. Aim is characterizing the habitability
of the Martian surface.
• This instrument has 3 ATS. These sensors have
been already implemented on REMS.
• The use of the ATS as a proxy for wind activity is a
novel application, and it is based on the use of an
intermediate value, the m parameter.
• Heat transfer convection h is dependent on the
local forced convection. It can be used to
characterize the wind.
• In this presentation, we will discuss in which way
the m parameter is related to the heat transfer
coefficient h.
The ExoMars rover. Credit: ESA

7. Cited Studies
• Important cited studies
S. No. Author Year Technique Outcome
1 D.W. Mueller Jr 2006
Applied Thermal
Engineering
Similar physical model is used. In this study, predictions and measurements
of the temperature along a fin cooled by natural convection and radiation are
reported.
2
Javier Gomez-
Elvira
2012 Space Science
In this study, REMS (The Environmental Sensor Suite for the Mars Science
Laboratory Rover) has been introduced. HABIT system is very similar to
REMS. And ATS sensors which used in the paper have been already
implemented on REMS.
3 Bonnie J. McBride 2002
Thermodynamic Data
Library
Used with the NASA Glenn computer program CEA (Chemical Equilibrium
with Applications) and used in the papers in order to comparison with the
analytical results.
u Other references have been cited for fundamental formula derivations.

8. Setup
• There are 3 rods and 3 ATS.
• Each ATS consists of a rod made of FR4 with a low thermal conductivity.
• Has three RTDs, at the base, at the tip and ¼ from the base.
• Each ATS 35 mm long

9. Mathematical Model
We are interested in this!

10. Mathematical Model
= Temperature at x
= Temperature of the fluid

11. Mathematical Model

12. Mathematical Model

13. Mathematical Model

14. Mathematical Model
(We know Tf)

15. Mathematical Model
How do you know the wind??

16. Mathematical Model
(We know Tf)

17. Experimental Backing
• Goal: To demonstrate that the values are of the same order of
magnitude, and that they change with wind speed and orientation as
expected.

18. Error in Paper!

19. Corrected Results from Figure 4

20. Experimental Backing

21. RESULTS and DISCUSSION
• The rise of convection coefficient values when the wind speed flow increase, both
numerically and theoretical. So, they are comprable.
• In the Nusselt number equation, temperature of fluid is used, instead of film
temperature.
• 1D and uniform heat flux is a simplification.
• Why the radiation is neglected in this calculation for Martian condition?

22. RESULTS and DISCUSSION
Although h radiation doesn’t change, the convection
coefficient values are changed by radiation effect.

23. RESULTS and DISCUSSION
• In addition, h convection coefficient values are not linear through the
fin. At table 6 and fig. 7;

24. CONCLUSIONS
ASSUMPTIONS;
• Nu number for a cylinder normal to the fluid flow
• Temperature and hc distributions along the ATS no 1D
• Convection coefficient calculated from two averaged values over control surfaces
for a non-linear distribution.

25. CONCLUSIONS
• ATS exposed to free flow Show a hc in agreement with the expected from the
model.
• The convective heat transfer and m value are increase according to speed of
wind.
• The different values of m parameters can be used to oriented and get speed of
the wind.
• This method is sensitive to describe wind types, so it can be used for getting
information about wind activity and heat fluxes.

26. CONCLUSIONS
• There are too many strong assumptions. These remove us the calculating more
accurate results.
• There are some mistakes at the part of results and graphics.
• Theoretical model is not applicable to this configuration.
• This paper isn’t cited anywhere.
• Always telling ATS «Sensors» which is a mistake

27. SUGESSTIONS
• Clarifying the definitions, and calculations.
• Some of assumptions are removed, because only a few depends on a references.
• Can have different Nusselt Number Correlations for higher accuracy for different Re
and Pr.

28. THANK YOU
CONVECTIVE HEAT TRANSFER MEASUREMENTS at the MARTIAN SURFACE