Opinion ID: 211242
Heading Depth: 4
Heading Rank: 1

Heading: Lueptow's Model Parameters

Text: 47 First, Vaughan argues that the modeling parameters were inaccurate. It notes specifically that the simulated Tank A and Tank G groupings in Lueptow's CFDs did not match or approximate many of the known tank parameters such as the height, flow rate, and nozzle diameter. Lueptow admitted that these parameters did not match the real-world parameters as Vaughan points out, but he also testified that the changes in the nozzle design would do little to disrupt the robust helical flow in the tanks. Furthermore, Lueptow performed a simulation of the Tank D parameters with different nozzle spacing and concluded that even though the parameters changed and some aspects of the flow changed, the helical flow was still present. 48 Vaughan appears to challenge the admissibility and reliability of Lueptow's expert scientific analysis and opinion. LD argues that our previous opinion reversing the district court's grant of summary judgment based on the genuine issue of material fact presented by the vector plots makes the evidence admissible under the law-of-the-case doctrine. Our previous opinion, LD I, did not directly consider the admissibility of the evidence, only that such evidence would be sufficient to create a genuine issue of material fact for trial. 355 F.3d at 1371. Issues not decided by the court in a prior proceeding are not covered by the law-of-the-case doctrine. Stearns v. Beckman Instruments, Inc., 737 F.2d 1565, 1568 (Fed.Cir.1984). Therefore, the admissibility of Lueptow's testimony had not been previously resolved. 49 Vaughan's challenges to expert testimony and scientific evidence are analyzed under the Supreme Court's Daubert factors. See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 589, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). When faced with expert scientific testimony, a district court must first determine whether the expert is proposing to testify to (1) scientific knowledge that (2) will assist the trier of fact to understand or determine a fact at issue. Id. at 592, 113 S.Ct. 2786. This requires an assessment of the reasoning and methodology underlying the testimony to determine whether it is scientifically valid. Id. In Daubert, the Supreme Court set forth four factors for district courts to consider when evaluating the validity and relevance of scientific evidence pursuant to Rule 702 of the Federal Rules of Evidence. Id. at 592-93, 113 S.Ct. 2786. These factors include (1) whether the methodology can and has been tested, (2) whether the methodology is subject to peer review, (3) the potential rate of error, and (4) the general acceptance of the methodology. Id. at 593-94, 113 S.Ct. 2786. The court further noted that the focus of a court's inquiry into the relevance and reliability of scientific evidence must be solely on principles and methodology, not on the conclusions that they generate. Id. at 595, 113 S.Ct. 2786. 50 Here, Vaughan's argument focuses on the parameters Lueptow applied, not on the reliability of CFD analysis in general. Indeed, CFD analysis has been previously recognized in the scientific community and has been recognized as reliable by at least one circuit. See Quiet Tech. DC-8, Inc. v. Hurel-Dubois UK Ltd., 326 F.3d 1333, 1343-44 (11th Cir.2003). In Quiet Tech., the appellant challenged the credibility of CFD analysis for modeling aerodynamic properties in a jet engine. Id. at 1344. The appellant argued that the expert used incorrect data or was missing data to run the CFD software and used the wrong equations to run his CFD analysis of the engine's aerodynamic properties. Id. Such a flawed analysis, it argued, made the testimony and evidence unreliable. Id. at 1344-45. The court held that such an attack goes more to the weight of the evidence than to its admissibility. The identification of such flaws in generally reliable scientific evidence is precisely the role of cross-examination. Id. at 1345; see also In re TMI Litig., 193 F.3d 613, 692 (3d Cir.1999) (`So long as the expert's testimony rests upon `good grounds,' it should be tested by the adversary process — competing expert testimony and active cross-examination — rather than excluded from jurors['] scrutiny for fear that they will not grasp its complexities or satisfactory [sic] weigh its inadequacies.' (quoting Ruiz-Troche v. Pepsi Cola of Puerto Rico Bottling Co., 161 F.3d 77, 85 (1st Cir.1998))); Wilmington v. J.I. Case Co., 793 F.2d 909, 920 (8th Cir.1986) (Virtually all the inadequacies in the expert's testimony urged here by [the defendant] were brought out forcefully at trial . . . . These matters go to the weight of the expert's testimony rather than to its admissibility.). 51 Here, Vaughan's challenge goes to the weight of the evidence rather than the admissibility of Lueptow's testimony and analysis. Though he admitted that his models did not exactly match the various accused tanks, this fact was fully discussed on cross examination. As in Quiet Tech., his models were not the perfect models of each individual tank, but they were based on reliable scientific methodology and subject to cross examination and the proffering of further scientific analysis by Vaughan. We conclude that a reasonable juror could consider Lueptow's testimony explaining the very robust, helical flow in the models and infer that the similar accused tanks will produce flow similar to the modeled flow. Therefore, we will not contravene the province of the jury by reweighing Lueptow's testimony. 52