Aircraft Cooling System Design

Flometrics designed the aircraft cooling system for a diesel powered UAV. The original aircraft was powered by air cooled gas engines which were upgraded. The manufacturer identified replacement engines, but they needed cooling for the radiators and intercoolers.

The first step in the design process was to calculate the pressure coefficient over the entire aircraft in order to determine the best location for cooling air inlets and outlets.

The above photo shows the pressure coefficients on the original aircraft based on computational fluid dynamics calculations (without propellers). This information was used to select locations for the various cooling inlets and outlets.

A scale model of the modified aircraft was fitted with prototype scoops, ducts, radiator and intercooler models and was tested in the wind tunnel with motorized propellers.

The flow through the scoops and ductwork was modeled in CFD to assure free flow of the cooling air.

Then the intercoolers and radiators were tested with realistic flows, temperatures and pressures in a laboratory environment. This bench testing resulted in minor modifications which resulted in optimal performance of the system.

Here is the aircraft at the end of the project, undergoing flight testing. It is now in full production. (Photo Courtesy PrimeZone Media Network)