Please explain to me how to solve this heat transfer problem with the theme of convection and with these considerations

a$)$ The solution must be presented in a clear and detailed manner, showing all the steps necessary to arrive at the answer. It is not enough to provide the final result; both the logical reasoning and the applied methodology will be evaluated.

b$)$ Specify all the equations used, describing the physical principles and associated assumptions, include diagrams, schemes or tables when necessary to illustrate your solution and always indicate the units at each stage of the calculations.

c$)$ Each technical decision must be specified and explained clearly, justifying why that option was adopted, explain how these decisions impact the design or performance of the system.

d$)$ Analyze the results obtained and relate your calculations to the physical phenomena that are occurring in the system, highlight any relevant interaction between the parameters and how these influence the thermal performance of the heat transfer system.

Problem:

An oil cooling system is installed in an aircraft. This system uses an air$-$oil heat exchanger. The oil, which circulates inside a bundle of tubes, must be kept below $80$C under cruising speed flight operating conditions. Air from the outside atmosphere passes outside the tubes to absorb the heat from the oil

Initial parameters.

a$)$ The oil mass flow is $0\mathrm{.}1$ kg$/$s entering at $120$C

b$)$ The air mass flow is $1\mathrm{.}2$ kg$/$s

c$)$ The exchanger is made up of tubes with a diameter of $10$ mm and a length of $1$ m

The engineer in charge suggests that a bank of $15$ tubes aligned with a separation of $2$ cm between them will be sufficient to ensure that the oil leaves at a temperature of $80$C or less. Analyze the viability of this proposal and, if necessary, propose improvements to the system design