A leading physics journal has decided to retract three research papers authored by Indian aerospace engineer Professor V.R. Sanal Kumar, citing serious concerns about the scientific validity of his work.
The journal Physics of Fluids, published by AIP Publishing, informed Kumar in May that it plans to retract three of his previously published papers centered around a controversial concept he termed “Sanal flow choking.” The editorial team noted that the decision followed a post-publication review which found that the central theory in the papers “fundamentally violates the second law of thermodynamics”—a foundational principle of physics.
The three affected articles include:
- The theoretical prediction of the boundary-layer-blockage and external flow choking at moving aircraft in ground effects (March 2021, 24 citations).
- Universal benchmark data of the three-dimensional boundary layer blockage and average friction coefficient for in silico code verification (April 2022, 12 citations).
- In vitro prediction of the lower/upper-critical biofluid flow choking index and in vivo demonstration of flow choking in the stenosis artery of the animal with air embolism (October 2022, 11 citations).
These works, all co-authored by Kumar, had attracted attention—and criticism—from parts of the scientific community. Critics labeled the central premise as “absolute nonsense,” and pointed out several inconsistencies in both methodology and interpretation.
This is not the first time Kumar’s work has come under scrutiny. AIP Advances, another journal from the same publisher, previously retracted a related study by Kumar in 2023. The Physics of Fluids editorial office cited this earlier retraction as a factor in launching a broader review of his publications.
In internal communications, the journal stated that the articles contain “significant issues affecting the reliability of the findings,” including citations of previously retracted papers and flaws in the theoretical framework. In one case, peer reviewers had originally advised substantial revisions before acceptance. Despite those concerns, the paper was later published and even highlighted as an “Editor’s Pick.”
The journal has not only moved toward retracting the three published papers, but has also placed five of Kumar’s other submissions on hold pending further investigation.
In response, Kumar strongly objected to the retraction notices. In a formal reply, he rejected the journal’s decision, defending the importance and originality of his research. He described the reasoning as a “misinterpretation” of his work and alleged a “coordinated, international campaign to sabotage a breakthrough scientific theory.” Kumar said he has filed a formal complaint with the Committee on Publication Ethics (COPE) and informed Indian authorities about the matter.
As of now, the journal has yet to officially mark the three articles as retracted and declined to comment further while the internal inquiry is ongoing.