Heat flux augmentation caused by surface imperfections in turbulent boundary layers

Aerodynamic heating of hypersonic vehicles is one of the key challenges needed to be overcome in the pursuit of hypersonic ascent, re-entry, or sustained flight. Small, unavoidable imperfections are always present on the surface of aircraft in the form of steps, gaps, and protuberances. These can lead to high levels of localised heat flux augmentation, up to many times the undisturbed level. Flat plate experiments have been carried out in the Oxford High Density Tunnel with the aim of characterising the heating effects caused by small scale protuberances and steps in turbulent boundary layers. The current work presents experimental heat flux augmentation data, an assessment of existing heat flux correlations, and introduces new engineering level correlations to describe heat flux augmentation for a range of surface geometries

Outlook and appraisal [August 1984]

Growth in the British economy came almost to a halt during the first half of this year. As a result , even a speedy resolution of the coal dispute would be unlikely to push the GDP growth rate this year above 2.5 Though much of July's interest rate increase has already been reversed, it is likely to prove more difficult to reverse the effects on the retail price index and thus attain the goal of H.5% inflation at the end of the year. The uncompetitive nature of the housing finance market makes a speedy and full unwinding of the recent rise in mortgage rates unlikely

The Scottish economy [August 1984]

Throughout much of the last two years the official view has been that the Scottish recession was less severe than that experienced in the United Kingdom as a whole. Indeed, the Secretary of State has proclaimed to a variety of audiences, including the House of Commons, that Scotland was, and still is , leading the country out of recession. This diagnosis has not met with universal approval, as it appears to be founded primarily on the growth of the Scottish electronics sector and on the smaller proportionate rise in unemployment which has occurred in Scotland than in Britain as a whole. This latter fact is not particularly surprising as the pre-recession level of unemployment in Scotland was markedly above that of the rest of Britain

The Scottish economy [November 1984]

With the inauguration of the quarterly Scottish Business Survey (SBS) in September there are now two regular and up-to-date indicators of trends in the Scottish industrial sector. The combination of the new survey and the long-standing CBI Industrial Trends Survey provides a comprehensive and up to date assessment of trends in Scottish industry

The Scottish economy [February 1985]

With the inauguration of the quarterly Scottish Business Survey (SBS) in September 1984 there are now two regular and up-to-date indicators of trends in the Scottish industrial sector. The combination of the new survey and the long-standing CBI Industrial Trends Survey provides a comprehensive assessment of trends in Scottish industry

Outlook and appraisal [February 1985]

During 1984 the British economy maintained the growth rate of 2.5% achieved in the latter part of 1983. Growth in 1984 was depressed by the coal dispute which meant the direct loss of mining income and output and an associated reduction in the overall demand for the output of sectors such as Metal Goods and Mechanical Engineering. Resolution of the miners' dispute in the early part of the year and a full return to work will, with the associated "rebound" in activity, lead to a growth rate for 1985 of around 3 The longer the dispute is prolonged, the closer UK growth to the end of 1985 will approach the underlying rate of about 2.

Outlook and appraisal [November 1984]

The British economy experienced little growth during the first nine months of 1984. The projected GDP growth rate of 2.5% for the year as a whole is primarily a result of a rapid spurt of growth in the latter half of 1983, with the higher level then being maintained, but scarcely improved on, in the first three quarters of this year

The Scottish economy [November 1985]

With the inauguration of the quarterly Scottish Business Survey (SBS) in September 1984 there are now two regular up-to-date indicators of trends in the Scottish industrial sector. The combination of the new survey and the long-standing CBI Industrial Trends Survey provides a comprehensive assessment of trends in Scottish industry

The British economy [November 1985]

In his November Statement the Chancellor of the Exchequer has forecast continuing expansion of the economy during 1986. The recent growth of exports and investment is not expected to be maintained but consumer spending, boosted by higher real earnings and tax cuts in the Spring Budget, will rise

Outlook and appraisal [November 1985]

The Scottish economy, like that of the UK as a whole, looks set to experience a substantial shift in the relative importance of the factors determining growth in the coming year. As discussed elsewhere in the Commentary (see British Economy), growth in the recent past has been driven mainly by the expansion of investment and exports. With the interrelated factors of sterling's strength and continuing high real UK interest rates operating against a background of some deceleration in the growth of world trade, the prospect is that these influences will be largely replaced by the re-emergence of consumers' expenditure as the principal determinant of growth