Carnahan developed and taught computer-aided design methods at Rice University and at the University of Houston. Courses included process design, computer-aided design, mathematical modeling and applied numerical methods.
- consultant to ChemShare, Simulation Sciences, and several technology-oriented software companies
- author of a system of proprietary programs, called PLDES (Pipe Line DESign)
- develops mathematical models for numerous clients, for steady state and for transient analysis
- expert in complex network analysis
- software enhancement consultant to Gas Processors Association (GPA) and American Gas Association (AGA)
- generated a series of enhanced industrial thermodynamic property programs, most notable of which is PROPERTIES 75, a program for estimating hydrocarbon mixture thermodynamic properties applicable to low temperature processing and LNG operations. PROPERTIES 75 is available to members of the Gas Processors Association (GPA).
Custom-designed software, specifically oriented to a client's needs and operations, is often developed in the course of many consultancy assignments.