Lab 4 v2 impianto combustibile relazione 2

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Politecnico di Milano Dipartimento di Scienze e Tecnologie Aerospaziali Corso di Impianti e Sistemi Aerospaziali Lab No. 4 Fuel System Michele Rampini (Matr.: 844471) [email protected] Anno Accademico 2017/2018 Abstract This report analyzes the fuel system of a twin-engined aircraft. It is composed by two pumps, two tanks, two tubes of equal length and diameter, and a cross-feed valve. The cross-feed valve is fundamental for safety reasons, because, in case of a pump failure, the other one must be able to provide enough fuel for both the engines. Contents 1 Nomenclature 1 2 Problem Analysis 2 2.1 Problem Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.2 Solution of the Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2.1 Fuel Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2.2 Pressure Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2.3 Pressure Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3 Results Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3.1 Normal Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3.2 Crossfeed Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Final Consideration 8 i 1 Nomenclature Coefficienti Adimensionali λ Head loss coefficient [−] K Minor loss coefficient [−] Grandezze Fisiche ρ Fuel density[ kg m3 ] D Pipe diameter [m] L Pipe length [m] pmax Maximum pressure at engine [MPa] pmin Minimum pressure at engine [MPa] Qmax Maximum flow to the single engine [ kg h ] Qmin Minimum flow to the single engine [ kg h ] 1 2 Problem Analysis Figure 2.1: Scheme of the Fuel System 2.1 Problem Description This report aims at choosing the best…