From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Preliminary investigation and calculations for a proposed Vee 8 C.I. 2-stroke tank engine.
| Identifier | ExFiles\Box 132\2\ scan0197 | |
| Date | 22th January 1941 | |
| Wd{Mr Wood/Mr Whitehead}/GSB.10/RS.{Sir Henry Royce's Secretary}22.1.41. PROPOSED VEE 8 C.I. 2-STROKE TANK ENGINE. (90° Bank Angle). 5."1 x 6."5 Conclusions from rough preliminary investigation, based on arbitrarily assumed flywheel 15" dia. x 3" wide x 9" bore and arbitrarily assumed flexibility between this flywheel and adjacent crank centre of .14 micro radians/lb.inch. Crankshaft is assumed of same scantlings as P.I. Vee 12 engine. Balance weight M.{Mr Moon / Mr Moore} of I. .9 (lb.inch2) [handwritten above: 386.4] for each end is assumed same for crankshafts (α) and (P) with 45° and with 22½° angles between crank planes respectively, although it will really be rather less for the 22½° angles. [Diagram of crank throws, labeled 1, 2, 3, 4.] [Diagram of angles, α = 45°, β = 22½°.] Equivalent mass system with M.{Mr Moon / Mr Moore} of I's in lb.inch2 [handwritten above: 386.4] units and flexibilities in μ radians/lb.inch is as below :- [Diagram of equivalent mass system with the following values:] M.{Mr Moon / Mr Moore} of I's: 9.52, 1.608 [handwritten: = J], .708, .708 Flexibilities: .14, .071, .071, .071 [handwritten: = flex'] Labels: N, 1, 2, 3, 4, 5 Approx. natural frequency with this system is rather less than N = 11700 (~/min.) for single node (at N) type. The 2 node frequency is rather greater than 27,000 (~/min.) The harmonic components of the exciting torque as regards gas pressure on pistons and on sleeves are assumed to be same as for Vee Twin Unit of P.I. engine, although present engine is C.I. An investigation of harmonic components of a C.I. cylinder is being made, but provisional justification for this assumption is given in my calculations of 13.1.41 comparing results for one P.I. cylinder with Nancy Klock's coefficients for Sulzer 2 Cycle Diesel in "Jour. App. Mechs." Dec.1940. | ||