The so-called Philadelphia Experiment of conspiracy lore has inspired a wealth of fiction over the years. One of those earliest works, perhaps surprisingly, turns to be a thriller. Published in 1977, Thin Air by George E. Simpson and Neal R. Burger has a lot going for it, on paper at least.
For one thing, it's not actually about the alleged Second World War military-scientific effort. Or, at least not as conspiracy theorists know it today. Simpson and Burger set their experiment a decade later during the Korean War, though, as we learn, its roots go back to the 1940s. There are some intriguing pre-echoes too of the later 1984 film The Philadelphia Experiment as the novel takes on a thriller plot set in the then-present day, and even the ending bears some resemblance to the film's climax.
Thin Air, though, is fundamentally an investigate thriller that feels like a 1970s SF take on NCIS at times. And it suffers from that as the plot becomes increasingly convoluted, seeing Naval investigator Commander Hammond dealing with an old flame whose husband sends him down a path that uncovers decades-old secrets involving the experiment that turns out to be not so much in the past. The novel is too long for its own good, by roughly 75-100 pages by my reckoning, not to mention incredibly dated even by thriller standards.
On the other hand, as an early exploration of something resembling the Philadelphia Experiment in fiction, and likely the basis of various versions of it, later on, it retains a certain amount of historical interest. For conspiracy buffs and thriller fans of a certain age, it'll be worth seeking out. Just know this isn't quite what you're expecting it to be.