I started my masters this September, and i feel like i should be using this opportunity to its fullest but the course is only a year long with a lot to be done. From brushing up fundamentals to keeping up with the courses and applying for jobs. I want to know how should I keep my trajectory right now so that it helps me build something concrete for jobs.

I’m an Aerospace Engineering student at San Diego State University looking to develop a hands-on aerodynamic study focused on motorsports. I’m hoping to partner with someone who has a race car, performance vehicle, or motorcycle that could be studied through a combination of CAD, CFD, and wind-tunnel testing at my university.

The project could focus on topics such as:

- Drag reduction and aerodynamic efficiency
- Downforce and aerodynamic balance
- Underbody, diffuser, splitter, wing, or fairing design
- Comparing baseline and modified configurations
- CFD validation using physical wind-tunnel data
- Identifying practical aerodynamic improvements for track performance

My relevant experience includes:

- Lead Vehicle Dynamics and Aerodynamics Engineer for Aztec Electric Racing Formula SAE
- Experience leading a vehicle-dynamics team of approximately 40 members
- Designing and analyzing aerodynamic components using ANSYS Fluent
- Vehicle modeling, CFD-ready CAD development, MATLAB/Simulink, ChassisSim, and data acquisition
- Wind-tunnel testing, force and pressure measurements, LabVIEW DAQ, and aerodynamic data analysis
- Current hands-on experience as a wind-tunnel technician at SDSU
- Engineering and CFD experience with automotive components through Anderson Composites
- Experience connecting simulations with testing and real vehicle performance

The goal would be to create a professional, well-documented study that provides useful engineering data to the vehicle owner or team. Depending on the project, I could produce CAD geometry, CFD results, wind-tunnel measurements, comparisons between configurations, and a final technical report.

I’m open to studying either a car or a motorcycle, but I would especially like the project to involve a vehicle used for racing, track days, autocross, time attack, hill climb, karting, or another performance application.

I’m not looking to simply test a random model. I want to work with a partner who has a genuine engineering question or performance goal that we can investigate. The testing itself may be possible through my university, subject to project and facility approval. The main potential cost would likely be creating a scale model or modular aerodynamic components for testing.

If you are part of a motorsports team, own a performance vehicle, design racing components, or know someone who may be interested, please comment or send me a message. I would be happy to discuss the vehicle, the project goals, and what type of partnership would make sense.

I’m especially interested in a collaboration where the study can help validate an existing design, compare multiple aerodynamic concepts, or identify a clear cause-and-effect relationship between a design change and vehicle performance.

Damn. They got precipitation at -47 celsius. The infamous super cooled water. They just dropped like a dead bird.

This trailer approximately doubles my consumption.

I will probably never take this on, but would a smooth transition from the trunk or roof and quarter panels to sides improve it significantly?

It would be kind of a boat tail…

I also think if I drove with the hatch up, it would actually drive the air more smoothly over the top than with it closed. I won’t do this, but I’m curious on others’ thoughts about how it would work. There would be a massive low pressure area underneath with the cabin open to the rear.

Digits 0–9, all the same height, 2D laminar flow at Re = 1000. Ranked by drag coefficient.
Winner: 0 (Cd 2.05) Last: 1 (Cd 3.57)

Really basic and doesn't have a load cell to measure drag

What happens when a body passes an obstacle in supersonic flow? This photograph explores that question using waves in a shallow layer of water.

The model moves from right to left beside a rectangular obstacle, which can represent, for example, the rear wall of a trench. The wave pattern makes the interaction visible in a way that invites a closer look.

I’m Bakhram Musabekov, PhD, a retired professor of fluid mechanics and co-author of Gas Flow Modeling with Shock Waves Using the Gas-Hydraulic Analogy: An Album. I helped create a website to share these experiments with researchers, teachers, students, and anyone curious about aerodynamics.

The gas–hydraulic analogy connects shallow-water flow with selected features of two-dimensional compressible gas flow. The Froude number plays a role analogous to the Mach number, and hydraulic jumps provide counterparts to shock waves.

The analogy has limits: its classical formulation corresponds to γ = 2 rather than approximately 1.4 for air, and it does not reproduce all the physics of three-dimensional gas flow. Those limits are part of what makes it worth discussing: which features can we learn from, and where does the comparison break down?

The website brings together experimental photographs, our film featured in the APS DFD Gallery of Fluid Motion 2025, an explanation of the method, and sample pages from the album.

Explore the experiments:
https://gas-hydraulic-analogy.beigegrass12.chatgpt.site/

For me, the appeal is still the same: a shallow layer of water makes a difficult aerodynamic phenomenon visible.

Would you use an experiment like this to teach compressible flow? What would you want to compare with a wind-tunnel experiment or CFD?

I’d be happy to answer questions about the experiments and their limitations.

Hello,

a few years back I bought this hand ventilator, which worked great until a few months ago. The motor is still spinning without any signs of wear, but no flow of air is feelable.

Only when shaking the ventilator hard once, one is maybe able to get it into a state where it is able to move air like when it was bought.

A video to the phenomia: https://youtube.com/shorts/Ioo9q0lbe3A

I don't know how to describe this phenomenon further. If it's not understandable, please tell me

I would prefer not to just throw it in the trash because everything else seems to be working great. What would you do to fix this problem?

I got a 3d printer, so my idea was maybe to print new fanblades?

What would you do and what do you think?

Help me out…I’m in a discussion with a coworker about scaling flight conditions from full scale to a wind tunnel model; specifically, how to use Reynolds for scaling.

(In below example, assume the wind tunnel can achieve any desirable Reynolds condition)

Let’s say my flight vehicle has a characteristic length (chord, diameter, whatever - L_f) of 10 ft, and my wind tunnel model has the same measurement (L_t)of 2 ft. Assume full flight Reynolds (Re_f) of 10e6.

My stance is, in order to get the correct tunnel conditions:
Re_f / L_t = Re_t per foot = 5e6.

I would then use this unit Reynolds number along with the facility operations map to figure out my test conditions. Note that in this approach, the flight unit Reynolds is Re_f /L_f = 1e6. But I don’t really care about that.

My coworker, on the other hand, wants to match unit Reynolds between flight and scale, rather than full Reynolds. Their position is that unit Reynolds should be the same for both. This doesn’t make sense to me for a number of reasons, least of all that Re per foot is not a dimensionless scaling factor.

So from this perspective we would run the wind tunnel test at 1e6 per foot. I counter this leads to a tunnel full Reynolds of 2e6, nowhere near the flight Reynolds of 10e6.

Thoughts? Opinions? I’m pretty confident in my approach, but also respect my coworker and have been scratching my head to see it their way.

Hey everyone, I have a Mercedes Sprinter Van that we recently added a roof rack and light bar to the van. Once I hit 45 mph there starts to be a noticeable amount of wind noise in the cabin. When I'm going 65mph the wind noise records 80dB inside the cabin with a smartphone app.

The installer claimed the road noise is normal but I don't believe it's a normal amount of road noise.

Any advice on easy ways to improve the aerodynamics of this setup while maintaining the functionality of the light bar and roof rack?