TOTOGASHVILI, N. Remotorizace lehkého sportovního letounu [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2020.

Posudek vedoucího

Löffelmann, František

Student worked mostly by himself. Several consultations were done on the beginning of the work and later distantly through mails, however, some serious issues remained. Consultation just before the deadline was already late to finalize engine mount design and its test plan. Problematic are these points: 1) Unclear comparison of potential engines and reasoning of the selected one. 2) Missing detailed description of flight envelope calculation according to CS-LSA, resp. ASTM F2245. 3) Many tables contain columns or rows without labels. 4) Approaches, input data, and pictures are not referenced in the text. List of references is not according to citation norm ISO 690. 5) Design and technical description of the engine mount is not sufficient for further use (missing tube dimensions, attachments design and dimensions, etc.). 6) Engine mount test plan does not involve calculation of the engine mount loads and selection of critical load cases to be tested, so that this point of assignment cannot be considered as fulfilled. Moreover, overall quality is decreased by many formal and stylistic mistakes, e.g. listing all equipment and avionics not related to the thesis, table in Picture 5.1 is out of the page and contains + or – fuel and baggage without exact amount, graph in the Figure 3.1 miss axis labels. Positive point is that student calculated flight performances in the chapter 4 in detail beyond thesis assignment. It’s a pity that calculated performances are not compared with aircraft with the original engine to validate obtained values and evaluate expected precision. As a result, I recommend rather to continue working on the thesis and submit new version with improvements listed above.

Posudek oponenta

Jebáček, Ivo

The main goal of the work was to replace the existing engine of PS-28 Sportcruiser aircraft with another one engine searched and chosen by the student, to do basic mass analysis, engine mount design as well as its strength analysis. After the first chapter meeting us with the Sportcruiser aircraft which is, I guess, rewritten form official company's webpage without any reference or link to the resource, the table with engines as Rotax 915, and others are mentioned, but the table format is strange and looks like taken from another diploma thesis but again, without any reference. Under the table, there is a dry statement: Czechsport company chose the Lycoming O-235. The word "chose" is written as "choosed" and it is clear, the work had no language correction. In this part of the diploma thesis, I miss too much any student's effort to describe a reason why they chose an engine like this. It was in one of the work goals and I have to evaluate this part as insufficient. It is not clear, in the chapter concerning the mass and balance analysis, how it is possible to have a result C.G. mostly in rear position (28%) when the new engine is for 40kg heavier than the original Rotax 912. Picture 5.1 All possibilities is out of margin and not readable, so nothing is clarified. CG and mass diagram do not look like a standard and this chapter is in my opinion insufficient too, moreover, the student showed his inability in graphic skills. In Chapter 4.3 is the drag polar calculation but the tables showed columns where the is DIV=0! instead of the number, and the whole aerodynamic calculation seems to be useless. At the end of this chapter, some graphs are showed but without any description or title, so nobody knows what they should represent. The last chapter is focused on the engine mount design but it is clear, the student has no idea how would be done the typical steel truss rod engine mount and the result is again unusable and even the design of the test cannot save it, because it is very far from the real test, because the student did not calculate any load and therefore could not have any idea of what forces to apply. Overall evaluation: - the main goals were not fulfilled - the student is not able to interpret his results - low or almost none good result - inability to work with literature and quotations, in the text there is no reference - the work arrangement is horrible and in the practice unusable Because of the reasons mentioned above, I do not recommend this final thesis to further evaluation.

eVSKP id 125359