OPTIMIZATION OF FRICTION FACTOR FOR AEROSPACE DUCT OF EQUIPMENT COOLING SYSTEM OF AIRCRAFT

This paper discuss about the optimized friction factor for aerospace duct of Equipment cooling system of aircraft. Equipment Cooling is provided to maintain assigned temperature conditions in equipment compartment for satisfactory working of Line Replaceable units (LRUs) which are installed inside equipment compartment. Force air cooling is provided to these LRUs using Air Conditioning system (ACS) air. During up gradation programmes of aircraft due to introduction of new LRUs, there remains a requirement of redistribution of flow through complex duct geometries to meet their additional cooling requirements. In the present practice, designers carryout the redistribution of flow of air through these complex ducts using Continuity & Bernoulli's equation assuming approximate friction factors of head loss which can lead to improper results. In this paper first theoretical calculation for duct with new LRUs is carried out with present practice. After Theoretical calculation, complex duct geometry with calculated diameter is fabricated. The fabricated complex duct is installed on ECS test Rig in similar way as in Aircraft to maintain transient condition. The experimental mass flow rate for each section is measured & recorded. The Experimental calculation of roughness of all pipes in Complex duct geometry is carried out by Profilometer. By using Swamy Jain equation, the friction factor and mass flow rate is calculated. The percentage deviation in mass flow rate in Theoretical, Experimental are calculated by Swamy Jain Equation is compared and deviation is observed. Taking Experimental mass flow rate is main criteria the optimized friction factor formula is derived and mass flow rate based on optimized friction factor is calculated. This optimized friction factor mass flow rate is compared with experimental and very close results obtained i.e. the percentage deviation is very less. This research aims to determine the optimized friction factor through Aerospace ducts.