Thursday, August 3, 2017

WSC 2017 Update: August 3rd

It's the first week since the teams list was released that we haven't had any dropouts! We're holding steady at 45 teams: 27 Challenger, 16 Cruiser, and 2 Adventure teams.

(Compare to a total of 43 teams that showed up in 2015: 29 Challenger, 11 Cruiser, and 3 Adventure teams)

Five upcoming unveiling events were announced this week: RVCE announced their unveiling for August 5th, NIT on the 6th, ITU on the 9th, Blue Sky on the 14th, and Adelaide University will unveil on August 29th. We already knew that NWU will unveil on the 22nd, JU on the 28th, and WSU on the 29th - so now we're up to eight unveiling events coming up in August. Mark your calendars!

Also several teams shipped this week: Principia, Kookmin, Kogakuin, Minnesota, and Illini have all shipped their cars out for Australia.

Challenger Class

Status: Unveiled! Michigan unveiled Novum on July 7th.

No news this week.

Status: Unveiled! Nuon unveiled Nuna 9 on July 25th.

No news this week.

4: Antakari

The team has been broadcasting live videos of assembling the car on their Facebook, which is pretty cool. The team assembled the upper and lower shells together for the first time earlier this week.

(image source)

7: Adelaide University

Status: Unveiling scheduled. The team has announced that Lumen II will be unveiled on August 29th.

8: Punch Powertrain

Status: Unveiled! Punch unveiled Punch Two on June 21st. It will ship for Australia around August 20th.

An astute anonymous reader pointed out some array trickery in the comments last week - although in appeared that Punch was doing a silicon array, that is not the case!

A full 4sqm Sunpower E60 array is 260 uncut cells. Looking at photos of Punch Two and counting solar cells, we can see that the array is 22 cells long and 10 cells wide with roughly a 15 x 3 cell block removed for the canopy - only 175 cells, nowhere close to 260! 4sqm * (175/260) = 2.69sqm of array area, which is almost exactly the amount allowed for multi-junction arrays.

Another big indicator that Punch is definitely not doing a silicon array is the way the array is trimmed next to the driver canopy:

(image source)

Those cells next to the driver aren't trimmed in any rational way. Cells are usually all trimmed in the same way such that the power output of all the trimmed cells match - see Twente's 2015 car for an example. I think it's clear that the recess in the top of the car is designed for different sizes of solar cells than are currently visible on the car, and that the array visible at the moment is a fake.

(Aside: It's possible that we're seeing some old/spare array modules that the team massacred for camouflage purposes... but if I had to guess, it's probably images of solar cells printed on paper and then encapsulated like a normal solar cell. I've seen this done before and it's nearly indistinguishable from a real array module unless you're up close and in bright sun.)

I didn't notice initially because it's so hard to pick out the scale of the cars this year... It looks so much like a 2015 car that I didn't realize how small it really is! You can get a little bit of a sense in this video around 0:16, but the team was pretty careful to not place the cars too close to each other.

The team didn't deny it when I asked about the array. So, that's right: three out of the top five teams from 2015 are doing tiny multi-junction arrays this year, and the last one (Tokai) is still an unknown!

10: Tokai

Still no news from Tokai. As I pointed out two weeks ago, their WSC team profile notes Panasonic solar cells - which presumably means the HIT silicon cells they've used for the last few races. This doesn't rule out a Kogakuin-style bullet car, however...

No news this week - and other than one teensy tweet showing some composites practice from early May, I haven't seen any signs of progress on the car.

15: WSU

Status: Unveiling scheduled. WSU announced an official unveiling date: August 29th.

WSU received some motor parts this week and is evidently still doing some composites work. It must be some smaller parts, because I think the team has already painted the main body of the car. My bet is wheel fairings, I always remember working on those up until the very last minute. To quote an even older solar car alumni than me: "Wheel fairings are like little baby solar cars strapped up underneath your solar car; they'll take as much time and effort to design and build as the entire rest of the car."

16: Stanford

Status: Unveiled! Stanford unveiled Sundae on July 1st.

Not much news this week, just a little more battery manufacturing.

18: UiTM EcoPhoton

No news this week.

20: Durham

Status: Shipped! Durham shipped their car to Australia on July 18th.

No news this week.

21: Twente

Status: Unveiled! Twente unveiled Red Shift on June 23rd.

Not much news from the team this week, just some more car testing.

The realization that Punch pulled a fast one on us with the array made me go back and double check - and I'm sure that Twente is definitely doing a 4sqm silicon car; no shenanigans here. Some infographics directly call out a 4sqm array, and we can verify it other ways:

For example, Red Shift is 4.27m long x 1.38m wide = 5.89sqm planform area. Subtract out the 4sqm array, and we're left with 1.89sqm of space left over for the driver canopy. This lines up closely with how much space the driver canopy took up on 2015's Red One: (4.5m *1.8m) - 6sqm = 2.1sqm.

We can also look at photos the team has posted - this photo sure looks to me like the array blank is cut for integer numbers of silicon cells (look at the back of the driver cockpit), and we can compare this photo of the bare upper to this photo of the car in the wind tunnel to verify that there's no funny business with the blacked-out part of the car not matching the actual shape of the indentation molded into the top for the array.

22: MDH

Status: Unveiled! The team unveiled way back on May 31st.

The team has received their battery cells.

25: Nagoya Institute of Technology

Status: unofficially Unveiled! No formal unveiling event yet, but the car was shown testing at Bridgestone's test track on July 15th. I think the formal unveiling is scheduled for August 6th.

The team has attached their solar array, and will be racing at Suzuka this weekend.

28: Neul-Hae-Rang

Status: Unveiled! The team unveiled Woong-bi on June 25th.

The team posted a few photos from their unveiling to Facebook, so we have a little more than that vertical video to look at now. Yep, looks just like the rendering that's on top of their WSC team profile.

29: Siam Tech (Edison)

Looks like the team is starting to work on their array.

32: Principia

Status: Unveiled, and Shipped! There wasn't a formal unveiling event, but Principia took Ra X to Formula Sun in Texas, July 3-8. The team shipped the car to Australia on August 1st.

34: RVCE

Status: Unveiling scheduled. Public unveiling of Arka is scheduled for August 5th.

37: Goko High School

No social media links, so no updates. The car appears to be finished.

38: North-West University

Status: Unveiling scheduled. Public unveiling of Naledi is scheduled for August 22nd.

No news this week.

43: Australia National University

No news this week.

46: Jonkoping University

Status: Unveiling scheduled. The team has announced on Facebook and Instagram that Solveig will be unveiled on August 28th.

EDIT August 29th: The chassis below was a test chassis, and pretty much all of my concerns were addressed in the chassis on the finished car

I ran across a video from the first half of May in which the team was presented with an award, and there's a pretty detailed video of their chassis. And... wow. This is going to be a ludicrously thin car, at least as far as the array airfoil is concerned. I guess that's not exactly a secret; they've been posting renders and photos on their Instagram since way back in mid March... but somehow I never realized exactly what they were building until I saw the video.

(Screenshot around 0:48)

That said, I'm left scratching my head about some details, and really worried about others. For example, I'm not sure what's going on with the steering linkage pictured above - but it gives me the heebies. Also, the weld quality leaves something to be desired:

(Screenshot around 1:08)
A big void in the weld, right on the top of the roll cage
(Screenshot around 1:37)
Not the greatest welds...

Also, why is the tube on the upper right of the driver compartment made out of three tubes sectioned together at different angles? It would be a lot stronger and lighter if it were a single tube straight down to the front suspension mount. And what on earth is going on with the front left suspension mount? Braking forces are going to load up the welds on either side of that front tube in bending, and that's a big moment arm:

wat

Whoever designed this chassis seems to have been allergic to trusses, or bracing in general. Consider the steering column mount: why is is only attached to one side of the driver compartment?? A few extra ounces of material to complete the span would enhance the rigidity of the chassis and make the driver compartment much more resistant to collapsing under side impacts. You could probably save weight overall by being able to reduce the wall thickness on that super-long unsupported tube on the upper right of the driver compartment.

(Screenshot around 1:15)
Why?!?

Long unbraced tubes will work if the wall thicknesses are high enough, but that's a real brute-force way of doing it - this chassis would be lighter and stronger if it was designed with truss-like structures throughout. Perhaps the special Docol steel that they were sponsored with wasn't available to the team as thin-wall tubing...?

(I'm actually a little curious about the properties of that tubing, as there doesn't appear to be a single bent tube in the entire structure - it's all sectioned, mitered, and re-welded. Formed tubing in the roll cage would have allowed it to conform much tighter to the driver's head, and resulted in a smaller canopy)

Anyway, there's a lot of strange stuff going on with this car. The team seems to have done a lot of test driving on the chassis, so hopefully it hold together all the way to Darwin... ¯\_(ツ)_/¯

70: Sonnenwagen Aachen

Status: Unveiled! The team unveiled Huawei Sonnenwagen on July 20th.

Not much news this week. If I'm translating this blog correctly, the team is going to hold a sendoff event for the car on August 18th.

71: Istanbul Technical University

Status: Unveiling scheduled. The team just announced on Facebook that their new car will be unveiled on August 9th.

72: Proton

The team posted some screenshots of extremely basic CAD of their suspension to Facebook.

I'm going to be really honest, I do not expect this team to show up in Darwin with a car capable of crossing the start line.

77: Blue Sky

Status: Unveiling scheduled. The team just announced on Facebook that their new car will be unveiled on August 14th.

82: Kookmin University

Status: Unveiled, and Shipped! Kookmin unveiled Taegeuk on July 7th, and just posted to Facebook that they have shipped their car to Australia.

88: Kogakuin University

Status: Unveiled, and Shipped! Kogakuin unveiled Wing on June 29th, and shipped the car on July 31st. The team is shipping to Adelaide, and they will be testing out the car on a mock race while heading north to Darwin.

One interesting photo surfaced in yet another news article about the testing Kogakuin and NIT did at Bridgestone:

(image source)

You can see how much larger the rear wheel well is than the front - this is to accommodate the swiveling of the rear tube axle.

Cruiser Class

5: SunSPEC

Status: Unveiled! Singapore Polytechnic unveiled SunSPEC 5 on July 21st.

Not much to report this week - a few new photos posted to Facebook.

9: PrISUm

Status: Unveiled! Iowa State unveiled Penumbra on June 2nd.

The team took the car to a wind tunnel recently. I'm really amused that they kept the headlights on in the tunnel...

Status: Unveiled! Bochum unveiled Blue.Cruiser on July 5th.

One of our comments last week pointed out that the car looks a lot like a Citroen DS, and I'm forced to agree:


The team is doing a lot of testing right now. We've also been provided a view of what the passenger compartment looks like when fully loaded.

14: Flinders

No news this week.

23: University of Tehran

The team was very active on their Instagram this week, including lots of photos of composite work. It looks like the body of the car might be mostly complete.

EDIT: Just after posting this, the team posted some more photos to Instagram. You can see here and here two very good images of the current state of the car. Still quite a ways to go...

30: Team Arrow

No news this week.

33: Cairo University

No news this week.

35: IVE Sophie

Status: Unveiled! IVE unveiled Sophie VI on July 1st.

No news this week.

40: Eindhoven

Status: Unveiled! Eindhoven unveiled Stella Vie on June 21st.

No news this week.

42: TAFE SA

No news this week.

45: Lodz

Status: Unveiled, and Shipped! Lodz unveiled Eagle Two on July 14th, and shipped to Australia on July 17th.

No news this week.

The team took their chassis for a short test drive a few days ago.

75: UNSW Sunswift

We don't expect an unveiling until September.

The team is currently hard at work manufacturing interior panels.

94: University of Minnesota

Status: Unveiled, and Shipped! Minnesota unveiled Eos II on July 11th, and shipped it out to Australia over the last weekend in July.

Status: Unveiled! KUAS unveiled Apollo VIII on June 29th.

KUAS has been posting a lot of workshop photos and videos to Facebook. In particular, they're hard at work manufacturing interior components (just like Sunswift), and have received their MPPTs.

Adventure Class

52: Illini Solar Car

Status: Shipped! Illini's car is looking pretty finished, and the team has packed up everything and shipped their stuff out for Australia.

53: Mississippi Choctaw High School

No news this week.

4 comments:

  1. ITU announced earlier today an unveiling on 9th August

    Nigel

    ReplyDelete
  2. Twente have done their race simulation weekend and posted the after movie.
    https://www.youtube.com/watch?v=5NBREJ4YiKU
    At 2:38 something interesting must have been visible as they have greyed out Red Shift while sitting on the road. What secret might that have been?

    Erik

    ReplyDelete
    Replies
    1. Same for extended periods starting at 0:38.

      *shrug* some teams are just stupidly paranoid about showing the inside of their car.

      I don't know why they'd stage an interview right in front of the open car or choose to use that 3-second drone shot only to grey out the car later. Looks dumb.

      Delete