BibTeX does not have the right entry for preprints. This is a hack for producing the correct reference:
@booklet{EasyChair:11179,
author = {Naveen Rao and Arunakumar Hunasanahally Sathyanarayana and U Pruthviraj and Shrikantha S Rao},
title = {REEF3D: an Open Source CFD Tool},
howpublished = {EasyChair Preprint 11179},
year = {EasyChair, 2023}}