Thanks, Steve. I assume that all three
measurements were at full throttle, right? (MAP ~=ambient air
pressure?)
Haven't you flown with a regular wood prop in the past? Was it
faster than the Warp Drive, or about the same speed?
And if I'm reading correctly, you still have your 'stock'
radiators installed & had just blocked off the airflow to the
stock coolers?
Charlie
On 11/22/2015 4:17 PM, Steven W. Boese wrote:
Charlie,
The following data can be forwarded to the VAF thread as you see fit:
The data are averages for stabilized cruise portions of cross country flights with a single 7x16.5x2.25" radiator core in a belly mounted scoop. The Altrak altitude hold was engaged and the data was recorded by the Dynon EFIS and EMS at 3 second intervals. The stock cooling air inlets were blocked with flat foam plugs with about 2 sq in openings in each to supply some air flow through the cowl.
RV-6A, wheel and gear leg fairings installed.
Mazda 13B engine, normally aspirated.
RWS RD1A PSRU, 2.18:1 reduction ratio.
Warp Drive HP propeller, 3 blade 68" dia, 16.5 degree pitch at tip.
Belly mounted scoop for cooling, containing coolant radiator and oil to coolant heat exchanger, variable air outlet.
Auxiliary coolant radiator in cowl, thermostat controlled coolant flow, variable air inlet.
Stabilized cruise averages:
date 8/15/2015 8/15/2015 8/16/2015
duration (min) 20 40 70
ALT (ft) 9530 11530 10593
DA (ft) 12446 14294 13078
OAT (deg F) 69 59 59
MAP (in Hg) 20.8 19.2 19.0
RPM 5747 5712 5591
CAS (knots) 116 112 112
TAS (knots) 145 143 141
FF (gal/hr) 8.75 8.15 7.76
wt (lb) 1745 1715 1710
Coolant T in from
cowl rad (deg F) 177 164 125
Coolant T in from
scoop rad (deg F) 184 181 179
Coolant T out (deg F) 190 187 185
Oil T out (deg F) 226 222 216
Oil T in (deg F) 205 202 198
As possible point of interest, a more recent test flight with a V shaped radiator with two 7x16.5x2.25" cores in the scoop was made. In the cruise condition with a 114 degree F air temperature rise through the scoop radiator, the aircraft TAS was 143 knots and the scoop outlet air velocity was measured to be 157 knots TAS.
Steve Boese
RV6A, 1986 13B NA, RD1A, EC2
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