Carnahan developed PLDES (Pipe Line DESign), a suite of software for modeling of fluid phase behavior and thermal hydraulic behavior of pipelines. PLDES includes NETWORK, PHASENET, METERS, CAVITY, HEADER and HOTOIL.

Carnahan served as consultant to CHEMSHARE (now WinSim) and to SIMULATION SCIENCES (now Invensys) on thermophysical property correlations and applied thermodynamics for process modeling and phase behavior. Carnahan served as technical advisor to the AGA Gas Transmission Measurement Committee during the revision and enhancement of ANSI/API 2530, AGA Report No. 3, entitled “Orifice Metering of Natural Gas and other related hydrocarbon fluids”.

We develop custom software for client's special applications.