Valencia see's yet another iteration of Adrian Newey's / Red Bull's vision of this years ultimate concept. This version of the Sidepod / Exhaust / Tunnel concept is the most expansive version to date, encompassing much more bodywork and floor area in order to create a airflow caption area above the diffuser. It's no secret that the Milton Keynes based outfit have been confused that their original iteration of this concept didn't work as planned. Red Bull have attempted numerous versions now in order to attain the effect they first desired at the start of the season, whilst the rest of the field are seemingly converging on the McLaren style exhaust outlet in order to achieve more rear end downforce. The idea of having this 'false' floor is to further create additional rear end downforce and help toward create a sealing effect.
We can see from the picture above that the exit slope of the sidepod has been increased in length this is to not only accommodate the extended tunnel section but also allow for the McLaren-esque exhuast channel that’s carved into the bodywork. This whole section is a multi faceted airflow conundrum with airflow interacting in many differing ways. In the picture below I have marked out how this flow is destined to work.
Please be aware this is an approximation to further help understand how the flows work and interact
The blue airflow shown coming around the side of the sidepod is destined for the first portion of the Tunnel (As the strake inside the tunnel separates the flow patterns) The strake is there to provide a boundary which creates a higher pressure region, this in effect speeds up the flow either side of the strake and encourages the first element of flow and in turn helps with the second channel of flow which is highlighted in a bolder blue colour.
Lastly as the Tunnel finishes there is a small gap between the sidepod's edge and the vertical floor strake. This area will act like a funnel and converge with the the downwash flow (orange) & exhaust flow (Red)
The green area depicts the last area of airflow for the floor and one that becomes more neutral due to the airflow being robbed by the Tunnel ahead of it.
The McLaren style exhaust channel (Airflow shown in red) helps to guide the airflow from the downwash (Airflow shown in orange) whilst speeding up the airflow of the Tunnel beneath
Moving inbound the flow converges with the airflow coming through the engine cover and exits just below the beam wing and above the diffuser. As we can see from @Khan_F1 's pictures above the exit here has changed from the Montreal spec in order to utilise the additional airflow at exit.
As we can see from the image above Red Bull were utilising a hole in the floor above the starter hole to expell air passing across the floor. This hole is now encompassed by the larger engine cover outlet in order to further funnel the tunnel flow through this area of the floor.
As I write this I'm still unable to find a rearward shot of the RB8 depicting the Diffuser area clear enough to see if there is a difference in design ethos without the tyre squirt ducts. The current diffuser however can be seen to be much more like the Lotus design with outer portion of the diffuser pointing outwards. This helps manage the outer portion of the diffuser flow which in turn manages the effects of tyre squirt towards the central channel of flow.
Images Copyright Sutton Images / AMuS / @Khan_F1