Direct-connect flow

Three types of combushon test facility are used to evaluate the combushon efficiencies of ducted rockets direct-connect flow (DCF) test, semi-freejet (SFJ) test, and freejet (FJ) test, as shown in Fig. 15.13. Pressurized heated air or cooled air is supplied to the DCF, SFJ, and FJ test facilihes. The pressure and temperature of the airflow are adjusted by means of an air control system to simulate the air condihons during flight of the ducted rocket projechle. In the case of the DCF test, the airflow is supplied to the ramburner from a pressurized air tank through a directly connected pipe. No air-intakes are used in the DCF test. Thus, the pressure and temperature of the air in the ramburner are as directly supplied from the pressurized air tank. No supersonic flow or shock waves are formed during the supply of air to the ramburner. In the DCF test, the combustion efficiency in the ramburner is measured as a function of the air-to-fuel flow ratio, s. The combustion charac-... 

Turbochargers use the expansion of exhaust gas to pump combustion air to an engine. Exhaust gas is directed through a set of nozzles to drive a turbine wheel. Directly connected to the exhaust turbine is an air compressor turbine that delivers combustion air to the power cylinders. Thus, back-pressure is put on the engine exhaust, reducing power slightly, but the net effect of the increase in air mass flow available for combustion i.s to increase horsepower. 

Flow recorder, meclianical type, with direct connected pressure recording pen, locally mounted. (Note llial in listing such a combination item in speeifications, etc., it would be written as FR-4 and PR-2, thereby treating each element as a separate entity)... 

When the static pressure in a moving fluid is to be determined, the measuring surface must be parallel to the direction of flow so that no kinetic energy is converted into pressure energy at the surface. If the fluid is flowing in a circular pipe the measuring surface must be perpendicular to the radial direction at any point. The pressure connection, which is known as a piezometer tube, should terminate flush with the wall of the pipe so that the flow is not disturbed the pressure is then measured near the walls where the velocity is a minimum and the reading would be subject only to a small error if the surface were not quite parallel to the direction of flow. A piezometer tube of narrow diameter is used for accurate measurements. 

Fig. 2.6.11 Flow dispersion profiles obtained with (a) a capillary, (b) with a model microfluidic chip device containing a channel enlargement, directly connected to a capillary and (c) with the same microfluidic chip connected to a capillary via a small mixing volume. A sketch of the model microfluidic device is placed at the right side of each image, drawn to...

Obviously a block is a single entry flow diagram and the basic blocks are tree-like. We need only see that the operations of block composition and block iteration preserve the property of being tree-like. If B is fearned by directly connecting node n of block by block composition to entry node of block Bj, clearly n is an ancestor of ej, so that if both and Bj are treelike, clearly B is tree-like. If B is formed by block iteration by directly connecting exit node n of Block B to entry node of, then n remains a descendant of in B, so if is tree-like then B is also tree-like. 

Now suppose that G is a single entry tree-like flow diagram let e be the entry node of G. Let dg be the number of direct connections in G from a node to either itself or an ancestor. If dg = 0, G is a tree and a tree is obviously a block. We proceed by induction on dg. Suppose dg = d a 1 and we have proven that G is a block for every single entry tree-like flow diagram G with... 

There is at least one node s in G - Sn directly connected to n s must be an ancestor of n. If any other node in G - Sn were directly connected to n, then two ancestors of n would be directly connected to n, a contradiction of the fact that G is tree-like. Essentially G is formed by block composition from G - Sn and Sn. Form G by removing all of Sn from G and replacing the connection from s to n by an exit out of G. Then G is clearly a single entry tree-like subgraph with dg, dg - 1 and hence by the induction hypothesis G is a block. Similarly, is a single entry tree-like flow diagram. Form S ... 

If a(P) = 0, there is nothing to prove. Assume that we have shown the result for any flow diagram G with a(G) d-1 and that a(P) = d > 1. Let n and m be any two nodes in P such that the direct connection from n to m is anomalous. Let G- be a graph isomorphic copy of Sm with entry node m of G mapped by the graph isomorphism f onto m. Now the direct connection from n to... 

A nozzle used for a rocket is composed of a convergent section and a divergent section. The connected part of these two nozzle sections is the minimum cross-sectional area termed the throat The convergent part is used to increase the flow velocity from subsonic to sonic velocity by reducing the pressure and temperature along the flow direction. The flow velocity reaches the sonic level at the throat and continues to increase to supersonic levels in the divergent part. Both the pressure and temperature of the combustion gas flow decrease along the flow direction. This nozzle flow occurs as an isentropic process. 

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