The largest open-source dataset of car designs, including their aerodynamics

Original Article ↗ Hacker News Discussion ↗

Researchers have released a large computational dataset of parametrically generated car shapes and their simulated aerodynamics to support AI and engineering work, though access and licensing are constrained by a non-commercial Creative Commons license and, in some cases, institutional login requirements. Commenters highlight a range of open-source tools for aerodynamic design—especially for hobby aircraft and model wings—and note that full CFD is often overkill compared with faster panel and vortex-lattice methods. The conversation broadens into how aerodynamics, battery weight, safety rules, and market pressures toward SUVs are shaping modern electric vehicle design, often at odds with demand for lighter, more economical family cars.

Open-source aerodynamics tools and methods

  • Multiple commenters recommend open-source tools for aircraft/RC/flying-wing design:
    • CFD: OpenFOAM (powerful but often overkill for hobby use).
    • 2D airfoils: XFOIL.
    • 3D / vortex lattice / panel methods: AVL, VSP Aero, XFLR5, FreeWake, Datcom.
    • Higher-level toolkit: AeroSandbox (GitHub).
  • Consensus: for “normal-ish” designs, panel / potential-flow models are much easier and faster than full CFD, and good enough for performance and stability estimates.
  • Emphasis that some aeronautics background is needed to interpret results and understand limitations.

Dataset scope, content, and access

  • Data is hosted on Harvard Dataverse and referenced GitHub; also mirrored at caemldatasets.org without access restrictions.
  • Dataset size is reported as “a few hundred gigabytes.”
  • Clarification that the dataset consists of parametric, randomized car-like shapes derived from a template, not CAD models of real production cars.
  • One linked paper describes it as a large multimodal car dataset with CFD simulations and deep learning benchmarks; practical downstream uses are not deeply discussed in the thread.

Licensing and “open source” controversy

  • Dataset is licensed under Creative Commons Attribution–NonCommercial (CC BY‑NC 4.0).
  • Several commenters argue that:
    • Non-commercial licenses are not “open source” under established definitions.
    • Calling it “open source” is misleading and waters down important legal concepts.
  • Others note:
    • CC BY‑NC still allows broad access, but restricts commercialization of the dataset.
    • There is ambiguity about whether using the data inside a commercial workflow (e.g., training models, designing a car) would violate “NC”; interpretations differ and remain unclear.

Car design, modularity, and aesthetics

  • Some lament that aerodynamics + regulation push all cars toward similar “blobs.”
  • Others welcome standardization and shared parts for cost and repair benefits, but note manufacturers have incentives to avoid interchangeable components to protect margins.
  • There is a tension between:
    • Desire for cheap, robust, standardized vehicles.
    • Desire for emotionally appealing, varied designs; several commenters feel current design trends are in a “dark age.”

EV size, weight, and efficiency debates

  • Extensive side discussion on why many modern EVs are heavy crossovers/SUVs:
    • Large, heavy battery packs to meet customer range expectations.
    • Consumer preference and profit margins for SUVs and crossovers.
    • Safety, crash standards, and “arms race” dynamics with larger vehicles.
  • Energy-density arguments:
    • One side cites ≈100× higher gravimetric energy density of gasoline vs batteries.
    • Another points out EVs’ higher drivetrain efficiency and regenerative braking, reducing the effective gap to around 5× in practice for usable energy.
    • Disagreement on whether that numerical refinement is “pedantic” or materially important.
  • Some argue ICE vehicles remain more mature and cost-effective; others claim certain EVs (e.g., mid-market crossovers) can already be more cost-effective than comparable ICE models.
  • Electric aircraft are mentioned as an example where battery weight and inability to “burn off” mass severely limit viability; landing-weight constraints exacerbate this.

Future EV architectures and packaging

  • Several comments note that many current EVs are adapted from ICE platforms, limiting efficiency and packaging gains.
  • Others highlight a shift toward EV-native platforms:
    • Examples cited (Tesla, Hyundai, etc.) and quotes from an automaker CEO promising “super-efficient platforms” with small exterior size but larger interior volume, and sub‑$40k or even sub‑$30k targets.
    • Suggestion that truly compact, efficient, family-friendly EVs may emerge within a few years.

Questions about aerodynamic extremes

  • A commenter asks how many of the ~8,000 shapes achieve very low drag coefficients (Cd < 0.20), citing a historical EV with Cd 0.19.
  • The thread does not provide an answer; distribution of Cd values in the dataset remains unclear.